An image forming apparatus including a patch detection sensor for detecting an intermediate transfer belt and image information of toner images transferred onto the intermediate transfer belt, a distance measurement sensor for detecting the distance between a light emitting portion of the patch detection sensor and the surface of the intermediate transfer belt facing the patch detection sensor, and a control unit for correcting the image information detected by the patch detection sensor based on the distance information detected by the distance measurement sensor and controlling image forming conditions so as to correct at least one of density and color misregistration of toner images based on the corrected image information.