A shutter device, which is capable of achieving power-saving when holding a shutter opening in an open state for a long time by mechanically inhibiting an operation of a second light shielding plate in a direction to close the shutter opening, is provided. The shutter device has a second light shielding plate locking member 37 displaceable to a locking position to inhibit a shutter opening closing operation of the second light shielding plates 10 to 13 and an unlocking position to allow the shutter opening closing operation of the second light shielding plates. The second light shielding plate locking member displaces to the locking position at a point of time when first light shielding plates 2 to 5 fully open the shutter opening, and displaces to the unlocking position immediately before the second light shielding plates start running.