An image forming apparatus capable of cleaning contact members by using developer leakage preventing components includes a photosensitive member, a developer feeding member which feeds a developer to supply the developer to the photosensitive member, contact members which keep a development gap or a development nip constant between the photosensitive member and the developer feeding member, and a sealing member which contacts the developer feeding member to prevent the developer from leaking. The sealing member may include cleaning portions which contact the contact members to clean a surface of the contact members. The sealing member may further include a sealing portion for preventing leakage of the developer, and cut portions which section the sealing portion from the cleaning portions. The cleaning portions may extend in a direction different from the sealing portion and contact the contact members.