PURPOSE: To reduce the generation of a vibrative noise by a blade, by drilling many mounting holes, which serves both as a mounting and a noise silencing hole, in the blade and fitting a diamond tip to be mounted to these mounting holes.

CONSTITUTION: A blade 1 is formed in an endless belt-shape by using a steel plate, mounting diamond tips 2 spacing a fixed distance on an edge line of the blade. Further the blade 1 provides mounting holes 4, and a rubber made protrusive object 3, having a protruding part in both sides providing a connection part 6 and containing a diamond grain, is removably fitted to be mounted to these mounting holes 4. This protrusive object 3, supporting the blade so as to prevent is from coming into contact with a cutting surface, concurrently grinds the cutting surface thus causing the generation of a vibrative noise to be suppressed.