An image forming apparatus includes a fixing side member disposed at a position on a fixing surface side of a sheet on which a toner image is formed; a back side supporting member that forms a fixing nip for conveying the sheet in a tightly sandwiching manner when the back side supporting member is in pressure contact with the fixing side member; and a voltage applying section that applies to both sides of the sheet passed through the fixing nip voltages opposite in polarity to surface potentials of the both sides.