To perform accurate cutting and notching on a corrugated pipe and to perform cutting of only a pipe on the outermost side without damaging an internal structure.

This tool comprises a guide cylinder 25 removably mounted on the outer periphery of a pipe material 23; and a rotary tool 27 rotatably engaging the outer periphery of the pipe material 23 with the guide cylinder 25 and having a cutting blade 47 movable radially of the pipe material 23. By effecting engagement between the guide cylinder 25 and the rotary tool 27 by a deviation preventing structure 29 to regulate a separate distance along a pipe material axis between the guide pipe 25 and the rotary tool 27 and the rotation locus of the rotary tool 27, and a notched depth regulation structure 31 to regulate rotation of a cutting blade 47 on the rotary tool 27, accurate cutting and notching of even the pipe material 23 the outside diameter of which is changed are practicable.