PURPOSE: To increase the speed of abrasion working by forcedly coating an object to be worked in advance or during working, and stopping a rise in a temperature.

CONSTITUTION: An object 7 to be worked is previously cooled by liquefied nitrogen, etc., and is placed on a two-axis stage 8 through a cooling means 10. The object 7 is irradiated by an ultraviolet laser beam la with a wavelength shorter than 400nm. Since a rise in the temperature of the object 7 is stopped, molecules composing the object 7 are decomposed by an abrasion phenomenon, and a material is locally removed without the occurrence of a thermal strain. The object 7 is moved in the Z direction by the two-axis stage 8 while it is irradiated by the pulse of the beam 1a, and the local removal of the material by the abrasion phenomenon is performed to the bottom surface of the object 7. Cutting is performed again to the bottom surface of the object 7 by stepwisely sending the two-axis stage 8 in the Y direction. The cutting working of the object 7 is completed by repeating successively this operation. Consequently, an irradiation energy density can be heightened.