Abstract: A mobile computer clean room satisfying all the temperature, humidity, and filtration constraints of a traditional "clean room" features a first portion (A) equipped with power supply means including battery means (17) and an inverter (18), and environmental control means including air conditioning (19) and particle filtration means, and a second, expandable, environmentally-controlled computer-receiving portion (B), having a double floor (4), and operatively coupled to said first portion, and means (2) for rolling said first and second portions from place to place to serve as an emergency service computer in the event that the computer normally in service finds itself momentarily out of service after a physical destruction (fire, explosion, flood).