The camera side mount is brought, by relative rotation with the accessory side mount, from a first state where each accessory side bayonet claw is inserted between the camera side bayonet claws into a second state where the camera side and accessory side bayonet claws engage with each other. The leaf spring biasing the camera side contact pins in the protruding direction is disposed between the camera side mount and the camera body. When the camera being in the normal position is viewed from the direction facing the camera side mount, the leaf spring extends from both sides of the mount center line, which extends from the center of the camera side mount in the direction of gravity, toward the camera side contact pins. The camera side contact pins are arranged at positions other than a position on the mount center line.