To adopt a crimping method for applying strong power and to facilitate both straight cutting and curved cutting at the same time by crimping and using a blade while letting a blade main body axis stand up almost perpendicularly to an object to be cut.

A lot of notches 3 are provided on one lateral side of the main body of a blade and on the rear side of these notches, a top end blade 4 is provided while being directed forward. An angle α formed from these top end blade and lateral side blade is set to be α >90°. Further, a folding groove -1 (5) and a folding groove -2(7) are provided and each time folding is performed along with these folding grooves, the tip part of the next top end blade or side blade is successively positioned at the front part of the main body of the blade. As a result, the blade can be used while letting the blade main body axis (almost the axis of cutter) stand up almost at 90° to the object to be cut, and it becomes suitable for straight cutting and curved cutting. Conventional use is enabled as well.