PURPOSE: To prevent waste of an unnecessary current, by starting an operation of an electronic timer, when the first stroke of a release button has been continously pushed for a prescribec time.

CONSTITUTION: When a switch 12 is closed by the first stroke of a release button, feed is executed to a photometric circuit 4, an operating circuit 5, a displaying circuit 6, etc. through a transistor 2. Subsequently, when an electronic timer 3 is used, a timer setting switch 20 is closed. In this state, when the first stroke is continuously pushed for a prescribed time, for instance, 0.1 second or longer, the timing circuit 3 detects it and starts its time counting operation. After that, even if a hand is released from the shutter button, feed to each circuit is held for a timer set time. In this way, even if the first stroke is pushed for a short time due to a malfunction, etc., the timer 3 does not start its operation, therefore, waste of an unnecessary current can be prevented.