Flanges are pressed into opposite ends of a photoreceptor drum. A noncontact charging roller is arranged so as to face, but have no direct contact with, the photoreceptor drum. On both end portions of the noncontact charging roller, spacers are provided for maintaing a gap between the photoreceptor drum and the noncontact charging roller. The spacers are of tape form and wound around the noncontact charging roller. Winding positions of the spacers are distant by more than an effective projection length of each of the flanges from respective opposite ends of the charging roller.