A seal member 264 prevents leakage of developer to the side of a photosensitive drum 10 when cleaning the surface of the photosensitive drum 10 of a color printer 1, and has a contact portion 264a and a movement control portion 264b. The contact portion 264a, through which developer is unable to pass, is able to deform elastically in a direction, and to approach and to separate from the surface of the photosensitive drum 10, able to be in line contact with the surface of the photosensitive drum 10 such that developer is unable to pass between the surface of the photosensitive drum 10 and the contact portion 264a. The movement control portion 264b is connected to the contact portion 264a, and configured to control the movement of the seal member 264 with the rotation of the photosensitive drum 10 of the contact portion 264a.