An image forming apparatus includes an image carrier, a transfer member, a power supply, and a control device that controls the power supply to output a DC-AC superimposed bias or a DC bias to transfer a toner image on the image carrier onto a recording medium. The control device controls the power supply to alternately output a first bias being a DC component the same in polarity as the DC bias and a second bias being a DC component opposite in polarity to the DC bias to clean the transfer member when image formation is not taking place. The first bias is output with two target output values including a first value and a second value lower than the first value. The second bias is output with one target output value. An output time of the second bias is longer than an output time of the first bias.