In the disclosed camera system, a spring arrangement to drive an automatic exposure mechanism of a camera and a magnet arrangement to control starting and stopping of the AE mechanism of the camera are provided within an electric drive device, and the automatic exposure control of the camera is carried out by mounting the electric drive device on the camera. Facilities, when energized by a power supply, are set to supply driving power to a motor for cocking the shutter, and an arrangement supplies power from the power source to the magnet arrangement for actuating the magnet arrangement. The present invention eliminates disadvantages of prior camera systems, namely, inferior response characteristic of the magnet and erroneous operations by the release action, and a large number of connecting terminals.