PURPOSE: To obtain an EE lock device which can be applied to the camera where a release button and a power switch are interlocked with each other, by holding the power supply state for a prescribed time after the operation for power supply release.

CONSTITUTION: A power switch SW1 is closed in accordance with the one-stage operation of a release button SW1A, and a counter C1 counts shutter seconds. When an EE lock switch SW9 is closed, AND gates A3 and A5 are closed by output inversion of NOR gates NR1 and NR2 which store the lock, and a counter C2 forming a timer is started, and the counting operation of the counter C1 is stopped. By the two-stage operation of the button SW1A for exposure photographing, the switch SW1 is opened. A transistor TR1 is turned on through the counter C2, an inverter I3, and a TR2 for a certain time from this time point to the end of the timer time of the counter C2, and the power supply state is continued, and thus, an EE lock device is obtained which is applied to the camera where the release button and the power switch are interlocked with each other.