# List of hardware manufacturers in the Essonne department

Tamtam tracks 114 hardware manufacturers headquartered in the Essonne department. This list ranks the 30 largest by number of employees on LinkedIn, led by Réseau DEF, DEF and HORIBA France. Their median headcount is 325. Half of them were founded in 1983 or later. The most common headquarters are Massy (10), Palaiseau (6) and Les Ulis (3).

The Essonne department hosts a concentration of hardware manufacturers, ranging from established industrial groups to specialized technology firms. Companies like Réseau DEF and DEF, both based in Massy, are prominent in fire safety systems. HORIBA France in Palaiseau manufactures measuring instruments, while ASN in Les Ulis specializes in optical submarine cable systems. TechnicAtome, located in Villiers-le-Bâcle, designs and maintains compact nuclear reactors, and Sebia in Lisses is a global leader in in vitro diagnostics.

This selection of companies highlights a strong presence in specialized manufacturing and engineering. There is a notable cluster of headquarters in Massy and Palaiseau, indicating these areas as key hubs for industrial activity within Essonne. The companies span various sectors, including defense, medical equipment, telecommunications, and automotive components, reflecting a diverse industrial landscape.

🇫🇷 Essonne · 30 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Réseau DEF](https://www.tamtam.ai/c/reseau-def) (reseau-def.com)<br>International network of expert companies providing detection, extinguishing, smoke extraction, and exit management systems through manufacturing and research facilities across several countries. | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Massy | 3,484 | 1958 |
| 2 | [DEF](https://www.tamtam.ai/c/def) (def-online.com)<br>French company, fire safety system solutions and services, from design to maintenance, including international sites and nuclear sector expertise. | Security Systems Services | 🇫🇷 Massy | 2,554 | 1958 |
| 3 | [HORIBA France](https://www.tamtam.ai/c/horiba-france) (horiba.com)<br>HORIBA France manufactures instruments to help individuals tackle all their challenges | Measuring and Control Instrument Manufacturing | 🇫🇷 Palaiseau | 2,200 |  |
| 4 | [ASN](https://www.tamtam.ai/c/asn) (asn.com)<br>Designs, installs, and maintains global optical submarine cable systems for telecom, content providers, and offshore oil and gas industries. | Telecommunications | 🇫🇷 Les Ulis | 1,717 | 1994 |
| 5 | [TechnicAtome](https://www.tamtam.ai/c/technicatome) (technicatome.com)<br>Specialized in compact nuclear reactor design, construction, and maintenance for various sectors including naval propulsion, research, medicine, and energy | Defense and Space Manufacturing | 🇫🇷 Villiers-le-Bâcle | 1,467 | 1972 |
| 6 | [Eurostyle Systems](https://www.tamtam.ai/c/eurostyle-systems-les-ulis) (eurostyle-systems.fr)<br>Design and production of industrial solutions specializing in high-precision plastics processing and leather materials for global automotive markets across fourteen production sites. | Manufacturing | 🇫🇷 Les Ulis | 1,158 | 1964 |
| 7 | [HORIBA for Materials](https://www.tamtam.ai/c/horiba-for-materials) (horiba.com)<br>Researching, developing new materials, improving manufacturing, and implementing recycling solutions for sustainability across the material supply chain. | Research Services | 🇫🇷 Palaiseau | 1,053 |  |
| 8 | [Sebia](https://www.tamtam.ai/c/sebia) (sebia.com)<br>Global specialty in vitro diagnostic leader for screening and monitoring various diseases, including oncology, diabetes, and autoimmunity. | Medical Equipment Manufacturing | 🇫🇷 Lisses | 1,018 | 1967 |
| 9 | [L-Acoustics](https://www.tamtam.ai/c/l-acoustics) (l-acoustics.com)<br>Leading manufacturer of professional sound solutions founded in 1984 near Paris, with presence in over 80 countries and specializing in modern line array technology and multichannel sound systems | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Marcoussis | 700 | 1984 |
| 10 | [Horoquartz](https://www.tamtam.ai/c/horoquartz) (horoquartz.com)<br>Provides integrated solutions for workforce management, planning optimization, activity tracking, access control, and identity management, serving over 5000 clients globally. | Software Development | 🇫🇷 Massy | 568 | 1971 |
| 11 | [record portes automatiques](https://www.tamtam.ai/c/record-portes-automatiques) (recorddoors.com)<br>Designs, manufactures, installs, and maintains a wide range of automatic doors and related products for commercial and institutional sectors. | Wholesale Building Materials | 🇫🇷 Champlan | 523 | 1970 |
| 12 | [ista France](https://www.tamtam.ai/c/ista-france) (ista.fr)<br>Global leader water and energy metering. Provides sustainable solutions for natural resource preservation, consumption individualization, diagnostics, and equipment maintenance in collective housing. | Smart Meter Manufacturing | 🇫🇷 Massy | 521 | 1872 |
| 13 | [Sector Alarm France](https://www.tamtam.ai/c/sector-alarm-france) (sectoralarm.fr)<br>Provides advanced alarm solutions and 24/7 security monitoring for residential and business clients across Europe with a focus on high customer satisfaction. | Security and Investigations | 🇫🇷 Massy | 434 | 2019 |
| 14 | [Vernet Group](https://www.tamtam.ai/c/vernet-group) (vernet-group.com)<br>Family company, world leader in thermal regulation, designing and manufacturing thermostats and thermostatic elements for automotive, heating, and plumbing industries. | Mechanical Or Industrial Engineering | 🇫🇷 Ollainville | 418 | 1927 |
| 15 | [Casio](https://www.tamtam.ai/c/casio) (casio.com)<br>Design and manufacture of consumer electronic products including watches, calculators, musical instruments, and other electronic devices for everyday use. | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Palaiseau | 325 | 2002 |
| 16 | [Pasqal](https://www.tamtam.ai/c/pasqal) (pasqal.com)<br>The company specializes in building programmable quantum simulators and computers using neutral atoms in optical tweezers for quantum information processing | IT Services and IT Consulting | 🇫🇷 Palaiseau | 297 | 2019 |
| 17 | [MIEL](https://www.tamtam.ai/c/miel) (miel.fr)<br>It imports and distributes advanced hi-tech products, offering technical assistance, training, and solutions for telecom and severe environments. | IT Services and IT Consulting | 🇫🇷 Bièvres | 277 | 1985 |
| 18 | [Exotrail](https://www.tamtam.ai/c/exotrail) (exotrail.com)<br>Develops and operates propulsion systems, mission simulation software, and orbital transfer vehicles for efficient, sustainable space mobility, enabling telecommunication, Earth observation, space exploration. | Defense and Space Manufacturing | 🇫🇷 Massy | 215 | 2015 |
| 19 | [UMS - United Monolithic Semiconductors](https://www.tamtam.ai/c/ums-united-monolithic-semiconductors) (ums-rf.com)<br>Designs and manufactures GaAs and GaN based RF and millimeter-wave integrated circuits and provides advanced foundry services for critical applications. | Semiconductor Manufacturing | 🇫🇷 Villebon-sur-Yvette | 210 | 1996 |
| 20 | [SOPHYSA](https://www.tamtam.ai/c/sophysa) (sophysa.com)<br>Develops neurosurgical implants, including adjustable valves for hydrocephalus and intracranial pressure monitoring systems, offering advanced solutions for neurological conditions. | Medical Equipment Manufacturing | 🇫🇷 Orsay | 195 | 1976 |
| 21 | [ADALTRA](https://www.tamtam.ai/c/adaltra) (adaltra.fr)<br>Specializing in communication systems for various environments such as offices, hotels, hospitals, airports, stadiums, and more, our solutions are designed by CAE GROUPE | Manufacturing | 🇫🇷 Massy | 182 |  |
| 22 | [AVL in France](https://www.tamtam.ai/c/avl-in-france) (avl.com)<br>Develops, simulates, and tests engines, transmissions, powertrains, and batteries. Provides turnkey test and simulation solutions, software, instrumentation, and services for the mobility industry. | Motor Vehicle Manufacturing | 🇫🇷 Palaiseau | 162 | 1990 |
| 23 | [Quandela](https://www.tamtam.ai/c/quandela) (quandela.com)<br>Specializing in photon-based quantum computing and cloud solutions to assist organizations in achieving quantum transformation | Nanotechnology Research | 🇫🇷 Massy | 157 | 2017 |
| 24 | [Composite Industrie S.A.](https://www.tamtam.ai/c/composite-industrie-s-a) (composite-industrie.com)<br>Specializes in manufacturing and repairing composite and hybrid metal-composite parts for aerospace, military, telecom, and transportation industries worldwide. | Aviation and Aerospace Component Manufacturing | 🇫🇷 Bondoufle | 128 | 1983 |
| 25 | [Elogen](https://www.tamtam.ai/c/elogen) (elogenh2.com)<br>Specialized technology provider designing, manufacturing, and maintaining hydrogen generators using water electrolysis with a focus on safety and meeting industry standards | Renewable Energy Equipment Manufacturing | 🇫🇷 Les Ulis | 127 | 2020 |
| 26 | [Sofradir](https://www.tamtam.ai/c/sofradir) (lynred.com)<br>Designs and manufactures high-quality infrared technologies for aerospace, defense, and commercial markets, including infrared detectors for military programs and commercial thermal imaging equipment. | Defense and Space Manufacturing | 🇫🇷 Palaiseau | 123 | 1986 |
| 27 | [BFR SYSTEMS](https://www.tamtam.ai/c/bfr-systems) (bfrsystems.com)<br>Design and supply of turnkey machines and production lines for food processing, packaging, handling, and quality control across multiple sectors. | Food and Beverage Manufacturing | 🇫🇷 Lisses | 122 | 1954 |
| 28 | [APILOG Automation](https://www.tamtam.ai/c/apilog-automation) (apilog.com)<br>Specialized in industrial and commercial automation integration, part of a larger group with expertise in civil engineering and construction, serving SMEs | IT Services and IT Consulting | 🇫🇷 Massy | 115 | 2004 |
| 29 | [KYOCERA Document Solutions France](https://www.tamtam.ai/c/kyocera-document-solutions-france) (kyoceradocumentsolutions.fr)<br>Provide comprehensive document management solutions including software, hardware, and professional services to support digital transformation and reduce environmental impact. | IT Services and IT Consulting | 🇫🇷 Massy | 113 | 1959 |
| 30 | [Sebia France](https://www.tamtam.ai/c/sebia-france) (sebia.com)<br>Development and manufacturing of in vitro diagnostic tools for disease detection and monitoring, focusing on oncology, diabetes, and rare diseases. | Medical Equipment Manufacturing | 🇫🇷 Lisses | 106 | 1967 |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.

## More company lists in the Essonne department

- [The largest companies in the Essonne department](https://www.tamtam.ai/l/largest-companies-essonne) (1,149)
- [Companies with in-house R&D in the Essonne department](https://www.tamtam.ai/l/r-and-d-companies-essonne) (198)
- [Multinational companies in the Essonne department](https://www.tamtam.ai/l/multinational-companies-essonne) (156)
- [Manufacturers in the Essonne department](https://www.tamtam.ai/l/manufacturers-essonne) (127)
- [Distributors and wholesalers in the Essonne department](https://www.tamtam.ai/l/distributors-and-wholesalers-essonne) (76)
- [IT Services and IT Consulting companies in the Essonne department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-essonne) (70)
- [Professional services firms in the Essonne department](https://www.tamtam.ai/l/professional-services-firms-essonne) (68)
- [Public sector organisations in the Essonne department](https://www.tamtam.ai/l/public-sector-organisations-essonne) (66)
- [Aerospace and defence companies in the Essonne department](https://www.tamtam.ai/l/aerospace-and-defense-companies-essonne) (65)
- [IT services companies in the Essonne department](https://www.tamtam.ai/l/it-services-companies-essonne) (60)
- [Retail chains in the Essonne department](https://www.tamtam.ai/l/retail-chains-essonne) (59)
- [Construction companies in the Essonne department](https://www.tamtam.ai/l/construction-companies-essonne) (56)
- [Software Development companies in the Essonne department](https://www.tamtam.ai/l/software-development-companies-essonne) (51)
- [Pharmaceutical companies in the Essonne department](https://www.tamtam.ai/l/pharmaceutical-companies-essonne) (45)
- [Electronics and semiconductor companies in the Essonne department](https://www.tamtam.ai/l/electronics-companies-essonne) (44)
- [Research institutes in the Essonne department](https://www.tamtam.ai/l/research-institutes-essonne) (42)
- [Events Services companies in the Essonne department](https://www.tamtam.ai/l/events-services-companies-essonne) (41)
- [SaaS companies in the Essonne department](https://www.tamtam.ai/l/saas-companies-essonne) (41)
- [Consulting firms in the Essonne department](https://www.tamtam.ai/l/consulting-firms-essonne) (40)
- [Family-owned companies in the Essonne department](https://www.tamtam.ai/l/family-owned-companies-essonne) (38)
- [Contract manufacturers in the Essonne department](https://www.tamtam.ai/l/contract-manufacturers-essonne) (35)
- [Research Services companies in the Essonne department](https://www.tamtam.ai/l/research-services-companies-essonne) (35)
- [Critical infrastructure operators in the Essonne department](https://www.tamtam.ai/l/critical-infrastructure-operators-essonne) (32)
- [Education providers in the Essonne department](https://www.tamtam.ai/l/education-companies-essonne) (30)

## The same list elsewhere in France

- [Hardware manufacturers in France](https://www.tamtam.ai/l/hardware-companies-france) (4,256)
- [Hardware manufacturers in Île-de-France](https://www.tamtam.ai/l/hardware-companies-ile-de-france) (1,142)
- [Hardware manufacturers in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/hardware-companies-auvergne-rhone-alpes) (794)
- [Hardware manufacturers in Grand Est](https://www.tamtam.ai/l/hardware-companies-grand-est) (342)
- [Hardware manufacturers in Occitanie](https://www.tamtam.ai/l/hardware-companies-occitanie) (291)
- [Hardware manufacturers in Nouvelle-Aquitaine](https://www.tamtam.ai/l/hardware-companies-nouvelle-aquitaine) (290)
- [Hardware manufacturers in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/hardware-companies-provence-alpes-cote-dazur) (263)
- [Hardware manufacturers in Pays de la Loire](https://www.tamtam.ai/l/hardware-companies-pays-de-la-loire) (251)
- [Hardware manufacturers in the Rhône department](https://www.tamtam.ai/l/hardware-companies-rhone) (243)
- [Hardware manufacturers in Hauts-de-France](https://www.tamtam.ai/l/hardware-companies-hauts-de-france) (212)
- [Hardware manufacturers in the Hauts-de-Seine department](https://www.tamtam.ai/l/hardware-companies-hauts-de-seine) (199)
- [Hardware manufacturers in Bourgogne-Franche-Comté](https://www.tamtam.ai/l/hardware-companies-bourgogne-franche-comte) (163)
- [Hardware manufacturers in Brittany](https://www.tamtam.ai/l/hardware-companies-brittany) (148)
- [Hardware manufacturers in the Isère department](https://www.tamtam.ai/l/hardware-companies-isere) (143)
- [Hardware manufacturers in the Bouches-du-Rhône department](https://www.tamtam.ai/l/hardware-companies-bouches-du-rhone) (142)
- [Hardware manufacturers in the Haute-Garonne department](https://www.tamtam.ai/l/hardware-companies-haute-garonne) (137)
- [Hardware manufacturers in Normandy](https://www.tamtam.ai/l/hardware-companies-normandy) (135)
- [Hardware manufacturers in Centre-Val de Loire](https://www.tamtam.ai/l/hardware-companies-centre-val-de-loire) (128)
- [Hardware manufacturers in the Nord department](https://www.tamtam.ai/l/hardware-companies-nord) (124)
- [Hardware manufacturers in the Yvelines department](https://www.tamtam.ai/l/hardware-companies-yvelines) (106)
- [Hardware manufacturers in the Gironde department](https://www.tamtam.ai/l/hardware-companies-gironde) (100)
- [Hardware manufacturers in the Loire-Atlantique department](https://www.tamtam.ai/l/hardware-companies-loire-atlantique) (86)
- [Hardware manufacturers in the Seine-et-Marne department](https://www.tamtam.ai/l/hardware-companies-seine-et-marne) (84)
- [Hardware manufacturers in Paris](https://www.tamtam.ai/l/hardware-companies-paris) (351)

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Source: https://www.tamtam.ai/l/hardware-companies-essonne