A process unit includes a photoreceptor drum, a frame and seal members. The photoreceptor drum has drum flanges protruded outwardly from both end surfaces of a substrate. The frame supports the photoreceptor drum rotatably. The seal members are provided between both end surfaces of the photoreceptor drum and the frame, and support the drum flanges. Each of the seal members includes an elastic member and a hard member. The elastic member and the hard member are adhered and laminated with each other in an axial direction of the photoreceptor drum. Furthermore, the hard member is arranged so as to be brought into contact with the photoreceptor drum.