An image forming apparatus includes an endless belt member; a drive unit moving the endless belt member; a first detecting unit detecting a rotating speed of the drive unit; a second detecting unit detecting an endless transport speed of the endless belt member; and a control unit controlling the rotating speed of the drive unit based on a first detection signal from the first detecting unit or a second detection signal from the second detecting unit selectively depending on a selection condition. Upon selection of the first detection signal in accordance with the selection condition, the control unit corrects the rotating speed of the drive unit using the second detection signal such that an average value of the endless transport speed of the endless belt member approaches a target average value.
