Pawls are formed on an outer peripheral portion of an operation dial at intervals equal to step rotating angles of the operation dial so that a user's finger nail can be placed on one of the pawls to rotate the dial. When the finger nail is placed on one of the pawls to rotate the operation dial, the finger nail placed on that pawl abuts against a stopper provided on a camera main body. Thus, rotation of the operation dial is stopped at each step rotating angle.