PURPOSE: To realize a normal operation, even when the fault bringing a temperature rise to the inside of an electrical apparatus which adopts a double configuration is generated.

CONSTITUTION: An electrical apparatus adopts a double configuration of a working system and a stand by system, and comprises a plurality of processing packages 2, 3 provided respectively with power supply parts 4 for themselves and one or plural cooling parts 6 which cool forcedly the inside of the apparatus. In the electrical apparatus, when the temperature of the inside of the electrical apparatus rises, the power feedings of the power supply parts 4 of the processing packages 3 of the preliminary system are cut off stepwise, while making one or plural steps, according to the temperature rise.