PURPOSE: To perform stable wire traveling with no slip as well as to make such a wire cut that is high in accuracy and excellent in efficiency performable, by dispersedly binding a coarse abrasive grain of more than #200 in grain size with a binder, and using a traveling roller with rough surface.

CONSTITUTION: If such a pinch roller 7 as being made up of having a simple or a mixed one of coarse SiC and other abrasive grains bound and molded with epoxy resin of the rest to 30-85% or so, or so as to form an uneven sur face, where abrasive grains are projected as much as about 2-30μ or so on the surface after being sintered and molded with a hyaline and others, is used, a friction effect becomes enhanced, while a wire electrode 1 will not cause any slip, and it can be traveled and driven at constant speed under stable ten sion. With this uneven surface, a contact area grows large, that is, current- energizing resistance is reduced to anout one-third as compared with the conven tional smooth surface roller, and an energizing current is incresable. In addition, the wire electrode 1 is also made into a roughened surface whereby discharge dispersiblity is hightened and stable discharge is performable, thus an erosion rate is improved.