PURPOSE: To prevent the supply of power unnecessary for an actuator to cause the operation of the door lock mechanism of an automobile.

CONSTITUTION: A door switch 2 is provided so as to open upon locking a door, and close upon unlocking the door. Also, a power supply instruction timer means 4 is provided so as to perform a time limit operation upon closure of the door switch 2, generate a power supply instruction signal upon completion of the time limit operation, and further perform a separate time limit operation upon the opening of the switch 2, and invalidate the power supply instruction signal, upon completion of the operation. Also, a timer control means 6 is provided so as to enable the time limit operation of the means 4, only when the travel speed of an automobile is equal to or above the predetermined value. In this case, when a change in the level of the power supply instruction signal is detected at the time of signal generation, the time limit operation of an actuator drive timer means 8 is made to start for power supply to an actuator 1 during the operation.