To shorten operation time by using a cutting device employing an air power source in place of surgery which uses a manually cutting device traditionally in the excision of bone, cartilage, tumor and the like.

A handpiece 10 has a head part 11 with a turbine housed therein at one end part thereof and a connection part connected to an air source connected at the other end part thereof. A cutting device 12 is beforehand mounted integrally on a rotating shaft of a turbine blade 13. An inert gas is supplied from the air source to rotate the cutting device 12 thereby cutting a bone or the like.