An image forming apparatus includes a first image forming unit, a second image forming unit. In combined processing to perform two types of processing including one-sided image formation and two-sided image formation, if the one-sided image formation is performed, an image is formed on one side of the sheet by the second image forming unit. If there is an execution request for a job of one-sided image formation processing different from a combined job of the combined processing during execution of the combined job, the image formation control unit, while performing the one-sided image formation in the combined job of the combined processing by the second image forming unit, performs the one-sided image formation related to the execution request for the job of the one-sided image formation processing different from the combined job by the first image forming unit and then discharges from the intermediate discharge unit a sheet which has undergone the one-sided image formation processing in the job different from the combined job.