To inexpensively provide a camera system in which a lens device driving an optical element according to the specification of imaging processing is detachably attached to a camera body, which cuts off the supply of power at the moment when the attachable and detachable lens device is detached from the camera body.

The lens device 110 includes: a connection terminal 213 which is electrically connected to the camera body 100; and a connection informing and specification receiving part 510 which informs the camera body 100 of the completion of electrical connection through the connection terminal 213 and receives the information on the specification transmitted through the connection terminal 213. The camera body 100 includes: a connection terminal 203 which is electrically connected to the connection terminal 213 provided on the side of the lens device 110; and a connection informing and specification transmitting part 440 which detects the completion of electrical connection to a lens driving part 500 through the connection terminal 203 and transmits the information on the specification to the lens driving part 500 through the connection terminal 213.