An alarm device control system in a camera having a metering device for measuring the brightness of an object and generating an output corresponding to a proper exposure value, and an alarm device for receiving the output of the metering device as input and giving an alarm when the proper exposure value does not satisfy predetermined photographing conditions. The system comprises switch means adapted to become operative in response to operation of a shutter release member, and a preparatory power source device for maintaining the metering device operative for a predetermined time after the switch means has become inoperative.