To solve the following problem; though a photoreceptor drum having a high hardness and a small wear amount is used in order to extend the endurance lifetime, when a cleaning blade is brought into contact with the photoreceptor drum having a hard smooth surface less liable to wear, faulty cleaning occurs owing to vibration and curl from a blade end and chipping of a blade edge.

In order to retain cleanability, a photoreceptor drum surface is ground by rubbing with a filmlike grinding sheet to form nearly circular linear grooves in a circumferential direction with a predetermined roughness value, and a C-roller having a hardness in a certain range and a surface roughness in a certain range is used as a C-roller for a contact charging system.