A full-color image forming apparatus for forming a toner image for each color on each image carrier, and for transferring the toner image onto a sheet, including: an image forming section for forming a correcting toner image for each color on a portion of an image carrier, wherein the portion corresponds to an interval between the successive sheets; and a control section for conducting a correcting operation of the toner image for each color, based on the correcting toner image which is formed by the image forming section, wherein, when the image forming section is possible to conduct an operation, if the image forming section is controlled to interrupt the correcting operation to use the correcting toner image yet to be formed, the control section controls the image forming section to form the residual correcting toner image, before the control section controls the image forming section to stop the operation.