An adapter includes: a first mount section that is detachably attached to a camera body; a second mount section that is provided separately from the first mount section and is detachably attached to an interchangeable lens; and an adapter control section that is capable of communicating between the camera body mounted on the first mount section and the interchangeable lens mounted on the second mount section. The adapter control section provides body transmission lens information for transmission to the camera body, on the basis of lens information requested from the camera body and lens information received from the interchangeable lens, through mutually different methods according to types of the lens information.