PURPOSE: To improve the grinding efficiency and the grinding accuracy with a metal and ceramics by irradiating a laser beam to the scarfing surface from the direction inclined thereto and blowing gas to said surface thereby blowing off the melt.

CONSTITUTION: The surface 2a to be scarfed of an object 2 to be scarfed is relatively moved while a laser beam 3 is irradiated thereto, and gas 4 is blown toward the position where the beam is irradiated. The beam is irradiated at 30W80° angle θ of irradiation in this stage. If the angle θ of irradiation is <30°, the scarffing efficiency decreses and if it exceeds 80°, an evaporating material and spatter intrude in an optical system. Air, oxygen, nitrogen, CO2, Ar, etc. are usable as blowing gas, and a nozzle 8 is used as a gas blowing means. A better effect is obtd. by directing the gas toward the position where the beam is irradiated from behind the relative moving direction of the beam 3. Precision grinding on a rolling roll under rolling is also possible.