A laser processing method for performing laser processing to a workpiece. The laser processing method includes: a filament forming step of applying a first pulsed laser beam having a transmission wavelength to the workpiece to thereby form a filament as an optical transmission line in the workpiece so that the filament extends from the surface of the workpiece to be irradiated with the first pulsed laser beam to the inside of the workpiece, the filament having a refractive index higher than that of the workpiece; and a laser processing step of applying a second pulsed laser beam to the filament after performing the filament forming step to thereby transmit the second pulsed laser beam along the filament, thereby processing the workpiece with the second pulsed laser beam.