A threading cutting insert achieves high shape accuracy of a screw to be processed, and saves on manufacturing cost. Therefore in the threading cutting insert, a plurality of tooth-shaped cutting edges are formed in a cross ridge line portion between a rake face and flanks formed in a cutting side face, wherein the plurality of mountain-shaped cutting edges provides at least one finishing cutting edge for transferring a shape of a screw, and at least one roughing cutting edge formed in a tooth shape smaller than that of the finishing cutting edge. A flank of the finishing cutting edge includes a first flank, and a second flank having a clearance angle larger than that of the first flank, wherein the finishing cutting edge, the first flank, and the second flank are sequentially provided in that order from the rake surface in a direction of a lower surface of the insert.