An image forming apparatus includes a developing device configured to develop an electrostatic image on an image carrier with developer, and a developer container detachably attachable to the image forming apparatus and configured to store developer to be supplied to the developing device. A developer supply unit is configured to supply the developer from the developer container to the developing device. The developer supply unit includes a developer detector configured to detect the amount of developer in the developer supply unit. The image forming apparatus controls the supply of developer transported via the developer supply unit and disables image formation on the basis of the detection result obtained from the developer detector. After the image formation is disabled, when the completion of the replacement of the developer container is detected, the image forming apparatus canceled the disabled image formation regardless of the detection result obtained from the developer detector.