An image forming apparatus includes a moving roller capable of axial movement; a medium end position detecting section for detection in the main scanning direction; and a control section for calculating the amount of misalignment of the medium from the detected end position; wherein the control section obtains the correction amount of the image forming position of the medium according to the amount of misalignment of the medium having been calculated, or the amount of misalignment of the medium and information of moving position of the roller, and provides control such that the medium or another medium coming later than the medium by a predetermined number of pages is moved by the moving roller by the difference between the correction amount of the image forming position and the amount of misalignment of the target medium, and the image forming position is corrected according to the correction amount.