An image bearing member unit and a developing unit are respectively configured to be attachable to and detachable from an apparatus main body of an image forming apparatus, the image bearing member unit has a first memory that stores information related to a toner amount during a toner supply in accordance with a drive amount of the image bearing member, the developing unit has a second memory that stores information related to a toner amount during the toner supply in accordance with a use amount of the developing unit, and a control device controls, during the toner supply, the toner supply with a toner amount based on the information stored in the first memory and the information stored in the second memory.