An image forming apparatus having a transfer device transferring a toner image from an intermediate transfer member to a sheet, a sheet feeder feeding the sheet to the transfer device, a sheet re-feeder, which reverses the front side and back side of the sheet to re-feed the sheet to the transfer device, and a controller, which controls the execution of a two-side copying mode, wherein when a feeding of the sheet from the sheet feeder is interrupted with a first toner image to be transferred to another sheet fed from the sheet re-feeder and a second toner image to be transferred to the sheet fed from the sheet feeder being on the intermediate transfer member, the controller controls the transfer device to perform a transfer of the first toner image and inhibit a transfer of the second toner image.