LASER BEAM MACHINING METHOD AND LASER BEAM MACHINING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a laser beam machining method and a laser beam machining apparatus capable of executing the fine machining on a surface and an inner side of a workpiece through which the beams in both regions of the terahertz region and the visible light region are transmitted in a short time and with high efficiency.SOLUTION: The laser beam machining method includes: a laser beam applying step of forming a modified area 50 with the physical properties being modified by forming a superimposed focal spot to the laser beam L, superimposing the focal point on a workpiece 5 through which the laser beam L is transmitted and applying the laser beam L thereto; and an etching step of removing the modified area 50.