An image forming apparatus includes a first unit including an image bearing member and a second unit. The second unit includes a developing roller to supply the toner to the image bearing member, a mounting portion in which the replenishing container is dismountably mounted, and an accommodating portion to accommodate the toner replenished from the replenishing container. The second unit is movable between a first position where the developing roller contacts the image bearing member and a second position where the developing roller separates from the image bearing member. When a moving direction in which the second unit moves from the first position toward the second position is defined as a separating direction, the second unit is urged in the separating direction by a force which the mounting portion receives from the replenishing container when the replenishing container is mounted to the mounting portion.