An image forming apparatus includes an image forming unit, a conveying unit and a control unit, the control unit has a function of image formation correcting of performing correction of the image forming unit in response to a reading result of an image on the transfer medium, and a function of prepurge processing of, when a paper jam occurs, performing control to discharge a valid medium located on a downstream side of a position where the paper jam occurs to outside the conveyance path and discharge a medium located on an upstream side of the position where the paper jam occurs to outside the conveyance path, and, when the paper jam occurs, and the medium being conveyed includes a medium for correction to be used for image formation correcting, the control unit performs control to perform the prepurge processing and continue the image formation correcting.