An electrophotographic photosensitive member has a cylindrical support, a photosensitive layer provided on the outer-periphery side of the cylindrical support, and an insert member inserted into the cylindrical support on its inner-periphery side. The insert member has a first surface on which the former is to be fitted in the cylindrical support and a second surface which is provided at least at one end of the insert member. The first surface and the second surface have a difference in level between them. The distance between the second surface and the inner periphery of the cylindrical support is larger than distance between the first surface and the inner periphery of the cylindrical support.