An image forming apparatus including: an output image forming section for forming an image and a pattern on a supporting medium under a prescribed condition; an output section for transferring the formed image on a recording sheet; a correction section for performing reading of the formed pattern and correcting the condition based on a result of the reading; and a correction control section for controlling operations of the output image forming section, the output section, and the correction section, wherein the correction control section identifies whether or not an area where the image is tobe formed and an area where the pattern is to be formed overlap each other, and when the areas are identified that they do not overlap each other, the correction control section controls the output image forming section to simultaneously form the image and the pattern in parallel on the supporting medium.