| 項目 |
英語 |
| AAEE | American Association of Electric Engineers |
| ABC粉末消火器 | - |
| ACB | air circuit breaker |
| ADP | apparatus dew point |
| ADPI | air distribution performance index |
| ADSL | asymmetric digital subscriber line |
| AD変換器 | AD converter |
| AFIダスト | American Filter Institute dust |
| AFI法効率 | AFI efficiency |
| AF工法ダクト | - |
| AGV | Automatic Guided Vehicle |
| AHU | Air Handling Unit |
| AI | Artifical Intelligence |
| AIA | The American Institute of Architects |
| ALC | autoclaved lightweight aerated concrete |
| AM | amplitude modulation |
| AMeDAS | Automated Meteorological Data Acquisition System |
| ANSI | American National Standards Institute |
| AS | air-break switch |
| ASHRAE | American Society of Heating、Refrigerating and Airconditioning Engineers |
| ASME | American Society of Mechanical Engineers |
| ASPE | American Society of Plumbing Engineers |
| ASSE | American Society of Sanitary Engineering |
| AVR | automatic voltage regulator |
| AVセンター | audio video center |
| AV会議室 | audio-visual conference room |
| AWG | American Wire Gauge Standard |
| A火災 | classA fire |
| A種ヒューズ | class A fuse |
| A種接地工事 | class A grounding work（10 ohms and below） |
| A種絶縁 | class A insulation |
| A重油 | bunker A、fuel oil A |
| a接点 | a-contact |
| A特性 | A scale |