An image forming apparatus includes an image carrier configured to carry thereon a developer image, an endless belt configured to be rotated while contacting the image carrier, a first cleaning roller having an outer surface made of semiconductor material and configured to electrically remove attachments attached on the endless belt, and a backup roller made of metal and arranged to oppose the first cleaning roller with the endless belt being interposed therebetween. The endless belt has a nip portion at which both the backup roller and the first cleaning roller contact the endless belt while opposing each other, and the first cleaning roller contacts the endless belt at a more upstream side than the nip portion in a moving direction of the endless belt.