PURPOSE: To continuously use a camera by applying shocks to an electromagnetic means by intermittently energizing the means plural times when shutter blades do not open to at least a prescribed opening even when shutter opening operations are made.

CONSTITUTION: Shutter blades 1 and 2 which respectively work as diaphragm blades are supported by shafts 1a and 2a in rotatable states pivotally. A blade opening/closing ring 3 is always energized in a counterclockwise direction by means of a spring 4 and pins 3a and 3b planted in the ring 3 are respectively engaged with long grooves 1b and 2b formed in the shutter blades 1 and 2. Moreover, a solenoid 5 which is an electromagnetic means for rotating the ring 3 counterclockwise is provided. When the shutter blades 1 and 2 do not open to at least a prescribed opening even when opening operations of the shutter blades 1 and 2 are performed, the electromagnetic means 5 controlling the opening/closing of the shutter blades 1 and 2 is intermittently energized so as to apply shocks to the means 5. Therefore, dust, water drops, etc., can be removed and the operation of the shutter blades 1 and 2 is not interrupted.