An image forming apparatus includes a transfer device to transfer a toner image formed on an image bearing member onto a recording medium, a sheet separation device to separate the recording medium from the image bearing member, a sheet separation bias application device to apply to the sheet separation device a sheet separation bias in which an alternating current (AC) component is superimposed on a direct current (DC) component, and a transfer bias application device to selectively apply to the transfer device one of a DC transfer bias having a DC component and a superimposed transfer bias in which an AC component is superimposed on a DC component. Upon application of the superimposed transfer bias to the transfer device, the sheet separation bias applied to the sheet separation device is changed from the sheet separation bias applied upon application of the DC transfer bias to the transfer device.