An exchangeable lens includes a holding portion where twelve lens connector terminals, each connected to one of the twelve body connector terminals and each having a contact area to come into contact with one of the body connector terminals, and at least one auxiliary lens terminal having a contact area are disposed therein so as to form a circular arc pattern relative to the amount center point. An interior angle formed by the contact area of the auxiliary lens terminal and the contact area of the eleventh lens connector terminal at the mount center point is smaller than an interior angle formed by the contact area of the first lens connector terminal and the contact area of the eleventh lens connector terminal at the mount center point.