A driving method of an electrophotographic type image forming apparatus is provided. The method includes forming an electrostatic latent image by operating a photoconductor and an exposure unit, developing the electrostatic latent image by operating a developing unit, and transferring the developed image to a paper, wherein the operation of the developing unit is stopped after a tail end of the electrostatic latent image passes through the developing nip. In addition, the operation of the developing unit is started at a predetermined time between the time when the paper begins to be transmitted and the time when a leading end of the electrostatic latent image reaches the developing nip.