To prevent the sticking of machining remainder substances jetted in opening a hole to a workpiece when a minute hole, such as an ink discharging nozzle hole of an ink jet printer, is opened using a laser beam.

An apparatus for laser beam machining comprises a laser beam radiating section for oscillating and radiating a laser beam, an optical section for condensing the laser beam on the workpiece, a jig section for holding and manipulating the workpiece, the protective body for closely sticking to the surface of the workpiece, and an image processing means for measuring the position of the workpiece.