A roll paper cutting device is attachable to the main body of an image forming apparatus main body. The roll paper cutting device includes a cutter for cutting the paper of a roll of paper contained therein, as well as an arrangement for feeding the cut sheet to the image forming apparatus. The roll paper cutting device has at least one transport roller for transporting the roll paper, as well as a drive system for driving the transport roller, and a drive change device such as a clutch for selectively bringing the transport roller into idle rotation or into a driven state. A detector detects the travel of the roll paper. A control device such as a CPU controls the rotation of the transport rollers with predetermined timing based on the time when the travel of the roll paper is detected with all the transport rollers in idle rotation in a standby state for paper feeding.