An image forming apparatus has an image bearing member, a developing agent image formed on the image bearing member, and transferring device for transferring the developing agent image onto a recording member. The image bearing member is cleaned, and the developing agent removed therefrom is stored in a container. A detection is performed as to whether or not the quantity of developing agent in the container has reached a predetermined state, and once the result of such detection becomes positive, the number of prints made thereafter is counted. The result of the detection and the result of the count are stored in a memory along with the container, and the image forming operation is controlled in accordance with the stored information. In another embodiment, the memory is stored in an attachable cartridge. The attachable cartridge has an image bearing member, a charger, a developing device, and a cleaning device.