An image forming apparatus includes a development container, a developer bearing member, first and second carrying members that carry developer, a supply device that supplies developer for replenishment, a discharge opening that discharges the developer contained in the development container, a controller that selectively performs one of a first mode and a second mode, a drive device that changes speeds for driving the first and second carrying members, and a counter that measures the number of sheets in the second mode. The controller sets the speed of the drive device in the second mode to be slower than in the first mode, and suspends the second mode and executes a mode for changing the speed of the drive device to a speed faster than in the second mode and driving the first and second carrying members for a predetermined time if a measurement result reaches a reference value.