To provide a flange for a cylindrical photoreceptor including a fine adjustment function capable of easily correcting the effect of the accumulated deviation occurring in shape accuracy and position accuracy in order to minimize the runout deviation at the surface of the photoreceptor mounted with the flange for the cylindrical photoreceptor.

This flange is constituted by installing a gear 1 to the backside of a seat part 2 having a disk shape and disposing a columnar bearing part 3 having a fitting surface 3a to be fitted into the fitting part of the cylindrical photoreceptor at the center of the seat surface 2a on the front side. The respective parts are so worked that the respective central axial lines of the gear 1 and the fitting surface 3a are aligned to the central axial line of a hole 5 for a revolving shaft penetrating the centers of the seat part 2 and the bearing part 3 and that the seat surface 2a is perpendicular to the central axial line of the hole 5. A projection 4 finely adjusted to an adequate height is disposed on the front surface of the seat surface 2a concentrically with the hole 5. This flange is used and is mounted at the photoreceptor by fitting the flange into the front end of the photoreceptor 4 in such a manner that the marginal surface of the photoreceptor comes into contact with the front end of the photoreceptor 4.