In the electric apparatus of the present invention, when the supply of electric power to a primary power supply circuit is started, a check is made to see if the apparatus has been turned ON by operation of a switch device S, by collation with the contents stored in a memory (not shown), and in accordance with the result of the collation a control system circuit makes control to continue or interrupt the supply of electric power to the primary power supply circuit. Therefore, in the case of a rise from an abnormal condition such as power failure, the supply of electric power to the primary power supply circuit can be interrupted rapidly. Thus, whether a trouble has occurred or not during power failure can be checked before resuming the operation and the occurrence of a danger can be prevented thereby.