An image forming apparatus of the present invention includes a developing device. In a case body of the developing device, a first storage chamber and a second storage chamber are formed. A first agitating screw is provided in the first storage chamber and a second agitating screw is provided in the second storage chamber. A developing roller is provided in the second storage chamber. A control portion controls driving of a first motor and a second motor. When toner installation is performed, the control portion controls driving of the first motor at a rotational speed higher than a rotational speed for development operation in a state where the second motor is stopped. When a certain condition is satisfied, the control portion starts control of driving of the second motor, to drive rotation of the second motor.