Abstract: A roll paper cutting apparatus in a printer whereby printed roll paper which has been printed and released can be cut certainly and smoothly with a simple structure. For this purpose, this roll paper cutting apparatus has a paper cutter comprising bite teeth which are provided on at least one of end portions thereof so as to start to cut released roll paper when it is held by an operator's hand, and cut teeth which are provided on a region different from a region of the bite teeth, the bite teeth and the cut teeth being located along a straight line, wherein the bite teeth are formed in such a manner that an angle between a line perpendicular to a row of the cut teeth and an outside surface contour line of each of the bite teeth is smaller than an angle between an inside surface contour line of the tooth on the other side and the perpendicular line. Preferably, the bite teeth have smaller pitches than the cut teeth.