An image forming apparatus includes a housing with an inner space, a photosensitive drum, a drum unit, a rail member, and a static eliminator. The photosensitive drum includes a rotating shaft, and a circumferential surface to be drivingly rotated around the rotating shaft for carrying an image thereon. The drum unit is inserted in the inner space of the housing along an axis direction of the rotating shaft in a state that the photosensitive drum is integrally supported to be mounted in the inner space. The rail member extends along the axis direction in the inner space for guiding the drum unit in the axis direction when the drum unit is mounted. The static eliminator is fixed to the rail member, and disposed to face the photosensitive drum in the drum unit mounted in the inner space for irradiating the circumferential surface of the photosensitive drum with static eliminating light.