Image forming apparatus having an opening/closing member that is prevented from closing when a replenishment container is attached to a process unit

An image forming apparatus to and from which a replenishment container accommodating developer is attachable and detachable, the image forming apparatus comprising:

• an opening/closing member;
• and
• a process unit including:
• an image bearing member configured to rotate while bearing a developer image;
• a developer bearing member configured to bear developer and supply the developer to the image bearing member;
• and
• a developer container configured to rotatably support the developer bearing member and including an accommodating portion configured to accommodate the developer to be borne on the developer bearing member,
• wherein the process unit includes a projection portion provided at one end portion thereof in a rotation axis direction of the image bearing member, the projection portion projecting upward more than a center portion of the process unit in the rotation axis direction,
• wherein the projection portion includes an attachment portion to and from which the replenishment container is attachable and detachable, the attachment portion being provided with a replenishment port through which the accommodating portion is replenished with the developer from the replenishment container,
• wherein the opening/closing member is movable between a closed position where the opening/closing member is closed to cover the attachment portion and an open position where the opening/closing member is opened to expose the attachment portion and where an attachment of the replenishment container to the attachment portion is allowed, the opening/closing member being prevented from being moved from the open position to the closed position by the replenishment container in a state that the replenishment container from which the accommodating portion has been replenished with the developer is attached to the developer container.