PURPOSE: To shape chips with good accuracy by providing a chip guide which bears dressing force in place of a gun support and restrains and positions the chips and cutter in specified positions.

CONSTITUTION: A chip dresser provided with a chip guide 40 is positioned with respect to a cutter 11 as chips C intrude respectively into bushings 46 when the chips are pressurized. If there is variance in the accuracy of stopping the chips C, the chips C are guided and corrected into the radial parts 47 in the bushings 46. Then the cutter 11 makes revolving operation to dress the chips. The dressing force in this stage is born by the guide 40 around the bushings 46 and is not acted at all to a welding gun and the support side thereof.