An image forming apparatus is provided with a photoconductor to have an electrostatic latent image formed thereon, a developing device for developing the electrostatic latent image with a toner, a toner replenishing device for replenishing the toner into the developing device, and a controller for controlling an image developing operation by the developing device and a toner replenishing operation by the toner replenishing device. The controller executes a non-replenishment mode for causing the developing device to perform image development without being replenished with the toner from the toner replenishing device, a discharge mode, following the non-replenishment mode, for discharging the toner remaining in the developing device and a refill mode, following the discharge mode, for refilling the toner into the developing device by the toner replenishing device.