LASER MACHINING METHOD

An objective of the present invention is to overcome the machining failure of a portion requiring the decrease of an X-Y table speed. By using a laser machining apparatus having an X-Y table (7) for mounting a workpiece (6), the X-Y table being movable in X and Y directions, a laser source (1) for emitting a continuous wave or a quasi-continuous wave laser beam, a modulator (3) for forming a pulsed laser beam (L2) by a high-speed modulation of the continuous wave or quasi-continuous wave laser beam (L1) emitted from the light source (1), and an optical system capable of converging the pulsed laser beam on the workpiece (6), a laser machining method for forming a groove having a predetermined pitch and performing a cutting work along a locus including a portion where the moving speed of the X-Y table is decreased is performed. Accordingly, a pulse width of the pulse laser beam is increased in accordance with the decrease in the moving speed of the X-Y table in the portion where the moving speed of the X-Y table is decreased.