Provided is an image forming apparatus which includes a photosensitive body on which an electrostatic latent image is formed, a developing unit including toner to develop the electrostatic latent image formed on the photosensitive body, a temperature sensor installed in the developing unit to measure temperature around the toner, a memory unit having information regarding the toner and installed in the developing unit to receive signals from the temperature sensor, and a controller electrically connected to the memory unit to control developing operations based on the temperature measured by the temperature sensor.