To prevent the generation of rust on the contact surface of rollers and to make it possible to attach, remove and replace an outer roller with respect to an inner roller under the state, wherein the outer roller is coupled with the inner roller in the processing rollers of a wire saw.

Processing rollers 13 and 14, wherein wires are wound at the specified pitch, are constituted of an inner roller 37, which is rotatably supported on a supporting shaft 36, and an outer roller 42, which is removably attached to the inner roller 37. The outer roller 42 has the double-layered structure of an inner core tube 43 and an outer groove forming tube 44. The inner roller 37 is formed of metal material, and the core tube 43 of the outer roller 42 is formed of an inorganic material different from the inner roller 37.