A barrier device in which excessive relative displacements of barrier blades in an optical axis direction are restricted to ensure a normal opening and closing operation of the barrier blades. The barrier device has second, first, and third barrier blades disposed in this order in the optical axis direction. Restriction portions of the first barrier blades have through portions extending from shielding portions in the optical axis direction and extending through elongated holes of the second barrier blades, and have extension portions extending parallel to the shielding portions from image-plane-side ends of the through portions and positioned on the image plane side of the second barrier blades. During the entire stroke of opening and closing of the barrier blades, the extension portions can be engaged with the shielding portions, whereby the second barrier blades are restricted from moving away from the first barrier blades.