PURPOSE: To simplify gap adjustment and to obtain a high-function and high- precision by providing a gap determining surface abutting on, at least, one of a developing unit, an electrifier, and a transfer unit and determining a gap with respect to an image carrier.

CONSTITUTION: The image carrier 1, the flange shaft part 31 of the image carrier, the electrifier 2, the developing unit 4, the transfer unit 5, and a bearing 21, are provided. At this time. the bearing 21 has the gap determining surfaces 21a-21c abutting on the developing unit 4, the electrifier 2, and the transfer unit 5, so that the developing unit 4, the electrifier 2, and the transfer unit 5 are only abutted/fixed on respective gap determining surfaces 21a-21c, to obtain a prescribed/required dimension. Even if each of the developing unit 4, the electrifier 2, and the transfer unit 5 does not have each gap adjusting function, an excellent result for an electrophotograpic process can be obtained by an electrophotograpic mechanism using the bearing 21.