A barrier device for covering and uncovering a front face of an optical system. The barrier device includes a rotating barrel supporting the optical system at an opening and rotatable about an axis, a barrier member that is movable by the rotation of the rotating barrel between a closed position covering the front face of an optical system and an open position uncovering the front face of the optical system, and an elastic member supported by the barrier member and coupled to the rotating barrel so as to transmit a rotational force of the rotating barrel to the barrier member. Accordingly, the number of dedicated parts for opening and closing the barrier member can be reduced, thereby attaining a reduction in cost and a reduction in configuration space. Further, the barrier device can be reduced in size.