An improvement in TTL metering system automatic control camera is disclosed. This type of camera requires a complicate control mechanism. According to the present invention, a substantial simplification of the mechanism is attained by providing the camera with a switch means interlocked with a shutter releasing operation and operable before the diaphragm being conrtrolled by a diaphragm control device, first and second holding circuits, a delay circuit, means for introducing the output of the first holding circuit into the diaphragm control device and means for introducing the output of the second holding circuit into a shutter control device.