PURPOSE: To permit the optimum cutting operation without stopping a running paper by a method wherein the direction of a fixed edge of a rotary cutter is fixed so as to be slanted by more than a right angle with respect to the running direction of the continuous paper to be cut while the rotating speed of the rotary cutter is changed in accordance with the running speed of the continuous paper.

CONSTITUTION: A printer is provided with a paper feeding roller 3 and a platen roller 4, which are driven by a driving motor 5 through a timing belt 6, a printing head 7, arranged above the platen roller 4, and a rotary cutter 8, provided at the rear side of the printing head 7. The rotary edge 82 of the cutter 8 is rotated by the driving of the same driving motor 5 through another timing belt 11 and a slip mechanism 10. In this case, the cutter 8 is arranged so as to be slanted by an angle θ shown by tanθ=TV/W when the cutting width of the cutter 8 is shown by W, the running speed of the continuous paper is shown by V and a cutting time is shown by T whereby the paper can be cut so that the cutting edge becomes parallel to the width of the paper.