To semipermanently stop supply of electric power by automatically and safely shutting down an electric apparatus without troubling a user if the electric apparatus has a voltage failure or an access operation which a user does not intend to do occurs.

A power supply interruption circuit 11 includes a latch relay 6, an Nch_FET 4, and a transistor 7. When a voltage detection circuit 9 and a user definition circuit 10 detect a failure, the transistor 7 is turned on and a switch 6c of the latch relay 6 is also turned on to turn off the Nch_FET 4 and to shut down voltage supply to a secondary main operation circuit 15. The latch relay 6, once the latch relay 6 is turned on, has a characteristic that the state is kept; therefore, power supply interruption can be semipermanently performed. At power supply restoration, the switch 6c of the latch relay 6 is turned off using latch relay control external terminals 16a, 16b.