A cutting unit has a support member having insertion holes, and a movable member having through holes connected thereto. The respective left sides of upper surfaces of the square through holes are first movable blades, and the respective right sides thereof are second movable blades. Firstly, the movable member 14 is moved to the right by a predetermined amount to cut peeled-off portions of segment end portions only, and then the movable member is moved to the left by a predetermined amount to cut peeled-off portions of the segment end portions only. Distal ends of the coil segments can be cut into a uniform length to enable high quality welding, through this process.