An image forming apparatus includes a photosensitive drum, a charging section, an exposure section, a developing section, an ion-conductive transfer roller, a transfer bias applying section configured to apply a transfer bias of reverse polarity to charge of toner to the transfer roller, a conveyance section, and a control section. The control section is configured to, during double-sided printing, cause the transfer bias applying section to apply a reverse bias of the same polarity as the charge of the toner to the transfer roller while a recording medium is reversed and conveyed again to a toner image transfer position.