A work area in which the air quality, temperature and humidity are highly regulated in order to protect sensitive equipment from contamination. Clean Room are important features in the production of silicon chips, hard disk drives and other technologies such as satellites. The air in a clean room is repeatedly filtered to remove dust particles and other impurities that can damage the production of highly sensitive technologies.

The measure of the air quality of a clean room is described in Federal Standard 209. Clean rooms are rated as "Class 10,000," where there exists no more than 10,000 particles larger than 0.5 microns in any given cubic foot of air; "Class 1000," where there exists no more than 1000 particles; and "Class 100," where there exists no more than 100 particles. Hard disk drive fabrication requires a Class 100 clean room.

People who work in clean rooms must wear special protective clothing called "bunny suits" that do not give off lint particles and prevent human skin and hair particles from entering the Clean Room Supplies 's atmosphere.