Image forming apparatus

Since a releasing unit for performing a separating operation of a transfer unit and a developing device from a drum unit and a releasing operation of an engagement state held by a holding unit as one operation is provided, the drum unit can be put in a drawable state at a drawing-out time of the drum unit from an apparatus main unit by performing one operation through the releasing unit, and since the releasing unit is constituted so as to cover a drawing-out unit provided on an image bearing member unit at a mounting time of image bearing member unit and release the drawing-out unit at a drawing-out time of the image bearing member unit, a user's erroneous operation can be prevented reliably, where improvement in safety can be achieved by preventing an erroneous operation while facilitating the drawing-out operation of the drum unit.