COVER FOR PROCESSING HEAD OF LASER BEAM MACHINE, PROCESSING HEAD WITH THE COVER ATTACHED THERETO, AND LASER PROCESSING METHOD FOR WORKPIECE

PROBLEM TO BE SOLVED: To effectively prevent laser beam or sputter, which is generated during laser machining, from being emitted or being dispersed outside.SOLUTION: A cover extends from an attaching section 1a attached to a laser processing head 2 to a workpiece W side and has a space inside thereof formed so as to cover at least the top side of irradiation nozzle 6. In the lower side from the lower middle section, a curved face 1g or an inclined face projecting downward is formed. A part of the curved face 1g or the inclined face works as a sliding contact face (bottom face part) 1f which slidably contacts with the surface of the workpiece during laser processing by the laser processing head. On the sliding contact face, an opening 1h is provided through which assist gas emitted from the tip of emitting nozzle and the laser beam can pass to the workpiece side. Between the attaching section or a section near the attaching section and the sliding contact face, an elastic section (a recessed groove 1b) is provided to reduce the distance between the attaching section and the sliding contact face when at least either the processing head or the workpiece moves relatively so as to reduce a distance between the attaching section and the sliding contact face.