According to an embodiment, an idler roller has an insertion through-hole through which a rotation shaft is inserted. Collar-shaped stopper portions are formed on the rotation shaft and are located on both left and right sides of the idler roller when the rotation shaft is inserted and provided at a normal position. Coil springs are attached between the stopper portions and base surfaces of concave groove portions of the idler roller. The idler roller is held at the normal position by biasing force of both the coil springs when paper is not seized. When paper is seized, the idler roller is moved in a lateral direction by elastic restoring force caused by a torsion phenomenon occurring in the paper. The idler roller returns to the normal position due to biasing force of both the coil springs after the paper has passed through the idler roller.