A camera system includes an interchangeable lens unit including an optical lens and an imaging device for taking an image of light from a subject having passed through the optical lens, a body unit to and from which the interchangeable lens unit is attachable and detachable, a setting information saving unit which is provided in each of the interchangeable lens unit and the body unit and saves part or all of pieces of setting information referred to in taking an image, a setting information choosing unit which chooses setting information to refer to, from the setting information saved in the interchangeable lens unit and the setting information saved in the body unit, and a setting information determination unit which determines whether or not the setting information saved in the body unit is applicable to the interchangeable lens unit.