An image forming apparatus disclosed includes a body, a cover to open and close an opening of the body, a plurality of photosensitive members provided in the body, a light scanning device to irradiate a light beam to the plurality of photosensitive members, the light scanning device including a plurality of passage windows corresponding to the plurality of photosensitive members, and a shutter device to open and close the respective passage windows in accordance with opening and closing movements of the cover.