To provide device and method for stabilizing the shape of an end face of a cutting ring at the time of cutting by a disk cutter and improving productivity, in manufacturing for a ring by cutting of a steel pipe.

In this multi-disk cutter type cutting machine, two cutting rings 17 are manufactured for one working cycle by press-cutting by the disk cutter 2 as necessary by sliding a tool rest 6 for supporting the disk cutter 2 at a tip in a slide direction 8 parallel to an axial direction of the steel pipe 1 as shown in a figure 1 and fixing the tool rest 6 at an arbitrary position.