Image forming apparatus

An image forming apparatus comprising:

• an apparatus main body including an image forming portion forming an image on a recording material by using developer;
• and
• a cartridge configured to be attachable to and detachable from the apparatus main body and capable of supplying the developer to the image forming portion,
• wherein the cartridge includes:
• a storage portion that stores the developer and includes a discharge port for the developer;
• a stirring member rotatably disposed inside the storage portion;
• a variable-volume pump disposed in the storage portion so as to form, together with the storage portion, a storage space for the developer in the cartridge;
• and
• a sealing member including a sealing portion attached to an inner wall of the storage portion so as to seal the discharge port in a case where the cartridge is unused, and a fixed portion fixed to the stirring member, the sealing member being configured such that the sealing portion is peeled off from the inner wall by rotation of the stirring member, and
• wherein the apparatus main body includes:
• a first drive portion providing the cartridge with a first driving force that drives the stirring member;
• and
• a second drive portion providing the cartridge with a second driving force that drives the pump, and
• wherein the second drive portion provides, in a case where the cartridge is unused, the cartridge with the second driving force after the first drive portion has started providing the first driving force, and the sealing portion is at least partially peeled off from the inner wall, and moreover the discharge port makes inside and outside of the storage portion communicate with each other.