The present invention relates to an image forming apparatus including an electrophotographic photosensitive member provided with a substantially cylindrical body having outer circumference on which a photosensitive layer with a latent image forming area is formed, and a contact electrification means positioned substantially parallel to the axial direction of the electrophotographic photosensitive member. A nip width of a contact area between the photosensitive layer and the electrification means is larger at a middle portion than at end portions of the latent image forming area. Preferably, the nip width becomes larger gradually or stepwise as proceeding from the end portions to the middle portion of the latent image forming area.