In printing, a first power supply unit applies a transfer current with a polarity opposite to a charged polarity of toner to the transfer roller. A second power supply unit applies a toner scattering suppression current with a polarity opposite to the charged polarity of the toner to a stretching roller until a rear end of a sheet passes through a separation position after a front end of the sheet reaches the separation position. The first power supply unit applies a post-transfer current, which has a polarity opposite to the charged polarity of the toner and has an absolute value equal to or more than an absolute value of the toner scattering suppression current, to the transfer roller until the rear end of the sheet passes through the separation position after the rear end of the sheet passes through the nip position.