PURPOSE: To prevent uneven rotation and to facilitate speed control, by fixing an optional weight to an optional position of a support with its end fixed to a rotary shaft and the other end fixed to the inner circumference in order to adjust balance of a photoreceptor.

CONSTITUTION: The balance-adjusting device 3 of a photoreceptor consists of a support member 4 having one end 4a of it fixed to a rotary shaft 2 and the other end 4b fixed to the inside wall 1' of a photoreceptor drum 1 with a screw 5, and a weight 6 fixed to an optional position of the support member 4 with a screw 7 and a nut 8. The member 4 can be fixed at any place of the inside wall 1' of the drum 1 with the screw 5 by rotation of the member 4, and the weight 6 can be fixed at any place on the member 4 with the screw 7 and the nut 8 by moving the weight 6, thus permitting imbalance of the photoreceptor to be adjusted, its uneven rotation to be prevented, and speed control to be facilitated.