PURPOSE: To provide a plastic material cutting processor which does not generate chatter vibration even in the case of cutting a plastic material and also facilitates cutting tool edge position and angle adjustment and also dissolves the disposal of scraps or the like.

CONSTITUTION: A cutting tool retaining member 2 having chip holder fitting portions 5, 6 is provided. A cutting tool 3 to furnish plural chips 8 at a chip holder 9 so that their contact angles with a material A to be cut may become gradually larger, is provided. A scrap cutting device 22 consisting of a scrap cutting movement edge 23 and a scrap cutting fixation edge 25 is provided. Cutting processing is carried out by feeding axially the material A to be cut while the member 2 is being rotated, and at the same time scraps are cut off by means of the device 22 at every one rotation of the member 2.