| Company | Location |
|---|---|
| ATMI Inc. | Danbury, Connecticut, United States |
| Atmospheric Process Plasma | Hwaseong-si, Gyeonggi-do, Korea |
| Atom Optoelectronics | Los Angeles, California, United States |
| Atomate Corp. | Santa Barbara, California, United States |
| Atomic Force F&E | Mannheim, Germany |
| Atomic-Scale Design Inc. | Westlake Village, California, United States |
| AtomWorks | Glencoe, Illinois, United States |
| ATOS GmbH | Pfungstadt, Germany |
| ATP Oil & Gas Corp. | Houston, Texas, United States |
| ATR Adaptive Communications Research Laboratories | Kyoto, Japan |
