A camera body includes a recess to which an image pickup unit is detachably attached to be placed therein. The image pickup unit includes a housing having an optical system, an image pickup device, a first connector section. The recess has three wall sections including a back wall section facing a rear of the housing of the image pickup unit and a side wall section facing a side surface of the housing when the image pickup unit is placed in the recess. The side wall section includes a second connector section to be connected to the first connector section to perform communication. The back wall section is provided with a controlling member. A rear of the image pickup unit has an insertion opening into which the controlling member is to be inserted and an abutting section to allow the controlling member to abut thereon. When the image pickup unit is attached to the recess, the first connector section and the second connector section are connected to each other when the controlling member is inserted into the insertion opening, and the first connector section is not connected to the second connector section when the controlling member abuts on the abutting section.