Disclosed is an image forming apparatus, which makes it possible to appropriately conduct a controlling operation for eliminating the velocity fluctuation of the photoreceptor drum without generating any malfunction. The apparatus includes a photoreceptor member driven by a motor and a control section that is provided with a feed forward controlling section that stores parameters derived from driving errors for one revolution of the photoreceptor member to create a reverse-phase instruction value based on the parameters and a feedback controlling section that controls a velocity of the photoreceptor member, so as to keep the velocity of the photoreceptor member constant. During an initial operating time, the control section deactivates the feed forward controlling section, while only activates the feedback controlling section to drive the photoreceptor member so as to measure a driving toque of the driving motor, and selects a parameter from the parameters, corresponding to the driving toque measured.