To provide a tip tool for cutting a rising pipe capable of easily and horizontally cutting a rising pipe at a predetermined position.

A disc cutter 2 is mounted to a tip 1a of an axial rod part 1 concentrically with an axis center L of the axial rod part 1. The axial rod part 1 is rotated on axis center L by a driving machine 4 connected to a base end 1b of the rod part and cuts a rising tube from within. To be more precise, a circular butt plate 5 externally fitted to the axial rod part 1 and a set screw 6 fitted into a screw hole 8 piercing from the outer peripheral surface to the inner peripheral surface of the circular butt plate 5 are provided, and on the axial rod part 1 a helical groove 7 in a direction opposite to a rotative direction by the driving machine 4 in a plan view is set from the base end 1b side to the tip 1a side of the axial rod part 1. The circular butt plate is fixed to the axial rod part 1 by making the tip of the set screw 6 project from the inner peripheral surface of the circular butt plate and press-contact a groove bottom part 7a of the helical groove 7 of the axial rod part 1. The rising pipe is cut while the surface 5a on the disc cutter 2 side of the circular butt plate 5 is made to contact an opening end surface of the rising pipe 3.