An image forming apparatus, comprises: a plurality of color image forming units each forming an image for correction for each different color on a different paper to output a correction chart; an operation unit for accepting an input of density correction instruction information corresponding to each of the plurality of color image forming units based on the correction chart; a control unit for setting color of the image for correction according to the density correction instruction information input by the operation unit, generating the image for correction for the set color, and causing the image for correction to be formed on the paper by the color image forming unit in order to output the correction chart; and a density unevenness correction unit for correcting density unevenness of each pixel in a main scanning direction for each of the plurality of color image forming units based on the density correction unevenness information input by the operation unit.