A photoconductive drum device is inserted into and removed from an image forming device main body, horizontally from a side of the image forming device main body. The photoconductive drum device includes a frame, a photoconductive drum and a cover. The photoconductive drum is supported rotatably on the frame under a state in which a part of an outer circumferential surface of the photoconductive drum is exposed. The cover is supported on the frame in a manner capable of swinging. In response to an insertion of the photoconductive drum device into the image forming device main body, the cover swings to an opened position so as not to block off a light path an exposure ray irradiated toward the exposed part of the photoconductive drum. In response to a removal of the photoconductive drum device from the image forming device main body, the cover swings to a closed position to cover the exposed part of the photoconductive drum.