A cartridge (B1) that is mountable to an apparatus main assembly (A1) of an image forming apparatus, the apparatus main assembly (A1) having mounted a photosensitive drum separate from the cartridge (B1), the cartridge (B1) comprising: a developing roller including an elastic layer for bearing developer (t), wherein the elastic layer can be pressured against the photosensitive drum ; a frame supporting the developing roller ; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame ; and an elastic part provided between the frame and the movable part to urge the movable part , wherein the movable part includes a first force receiving part configured to receive a first external force from the apparatus main assembly (A1), in a direction of moving from the first position to the second position, and a second force receiving part configured to receive a second external force from the apparatus main assembly (A1), in a direction of moving from the second position to the first position, wherein, when the movable part receives the first external force from the apparatus main assembly (A1) at the first force receiving part and is at the second position, the movable part receives an urging force (F10) from the elastic part in a direction of moving the movable part from the second position to the first position, wherein the first force receiving part is configured to receive the first external force from the apparatus main assembly (A1) so that, in a state that the cartridge (B1) is mounted on the apparatus main assembly (A1), the movable part is at the second position and the elastic layer is pressured against the photosensitive drum via the elastic part and the frame , and wherein the second force receiving part is configured to receive the second external force from the apparatus main assembly (A1) so that, in a state that the cartridge (B1) is mounted on the apparatus main assembly (A1), the movable part is at the first position and the elastic layer is spaced from the photosensitive drum . a developing roller including an elastic layer for bearing developer (t), wherein the elastic layer can be pressured against the photosensitive drum ; a frame supporting the developing roller ; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame ; and an elastic part provided between the frame and the movable part to urge the movable part , wherein the movable part includes a first force receiving part configured to receive a first external force from the apparatus main assembly (A1), in a direction of moving from the first position to the second position, and a second force receiving part configured to receive a second external force from the apparatus main assembly (A1), in a direction of moving from the second position to the first position, wherein, when the movable part receives the first external force from the apparatus main assembly (A1) at the first force receiving part and is at the second position, the movable part receives an urging force (F10) from the elastic part in a direction of moving the movable part from the second position to the first position, wherein the first force receiving part is configured to receive the first external force from the apparatus main assembly (A1) so that, in a state that the cartridge (B1) is mounted on the apparatus main assembly (A1), the movable part is at the second position and the elastic layer is pressured against the photosensitive drum via the elastic part and the frame , and wherein the second force receiving part is configured to receive the second external force from the apparatus main assembly (A1) so that, in a state that the cartridge (B1) is mounted on the apparatus main assembly (A1), the movable part is at the first position and the elastic layer is spaced from the photosensitive drum . <EOS>