To surely switch a diaphragm.

A shutter lever presser 67 and a charge lever 69 are arranged in a shutter mechanism. By feeding photographic film, the shutter lever presser 67 is pressed by a cam 74 and rotated to a charge position. At such a time, a pressing lever 81 provided on the charge lever 69 abuts on the pressing part 59c of a diaphragm lever 59 so as to rotate the diaphragm aperture of a diaphragm plate from a large diaphragm position to a small diaphragm position. An iron piece is fixed on the pressing part 59c of the diaphragm lever 59 and made to abut on the iron core of a latch solenoid set at the small diaphragm position. At the time of photographing, the latch solenoid is energized and the diaphragm plate is held at the small diaphragm position when the photometric value of a subject image is larger than a set value, and the diaphragm plate is moved to the large diaphragm position by the energizing force of a spring when the photometric value is smaller than the set value.