A flash lever for actuating a flash switch is interlocked with a stop plate via a spring. When a picture is taken without a flash, photographing is performed in a state that a small stop opening of the stop plate is disposed at an optical path. When the flash lever is moved to an ON position in order to take a picture with the flash, the flash switch is turned on to activate a flash circuit and a photometry circuit. At this time, the stop plate is evacuated from the optical path so that photographing is performed only through a fixed stop opening. If luminance of a subject is large in this condition, an electric current is supplied to an electromagnet to pull an iron plunger therein for returning the stop plate to the original position. In virtue of this, photographing is performed through the small stop opening.