A suppressing interference with the irradiation of the subsequent laser beam by debris or the like generated by irradiation of the preceding laser beam.
A laser machining apparatus comprising a laser beam irradiation unit for irradiating a laser beam oscillated by the oscillator laser beam a plurality of laser beams formed is branched by the branching unit to the wafer held on the chuck table through the condenser lens used, a laser processing method of the wafer for processing the wafer which is divided by a plurality of dividing lines are set in a lattice pattern on the surface, irradiating the wafer along the laser beam of the plurality of the said dividing line and, machining a groove along the dividing lines comprising a groove forming step of forming on the wafer, the processing in the groove forming step, a laser beam of the plurality of branched by the laser beam branching unit, the laser of the plurality of arranged in rows relative to the extension direction of the dividing lines beam is irradiated to the non-parallel directions .
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