An electrophotographic image forming apparatus including an image bearing member which is a rotatable photoconductor containing an organic photoconductive layer on a conductive cylindrical support, a latent electrostatic image forming unit configured to charge the image bearing member to form a latent electrostatic image thereon, and a developing unit configured to develop the latent electrostatic image on the image bearing member with a developer to form a visible image, wherein the thickness of the organic photoconductive layer monotonically decreases or increases along the rotational axis from one end to the other end, wherein the developing unit includes a development sleeve for bearing and transferring the developer to a developing region, and wherein a development gap is formed between the image bearing member and the development sleeve, and becomes narrower from one end where the organic photoconductive layer is thicker to the other end where the organic photoconductive layer is thinner.