WORKING HEAD OF FIBER LASER PROCESSING MACHINE

PROBLEM TO BE SOLVED: To provide a working head of a fiber laser processing machine, in which an optical element of an optical control unit can be protected from contamination.SOLUTION: The working head 10 of the fiber laser beam machine is equipped with a head body 11, a lens barrel unit 20 housed in the head body and controlling condensation of laser light emitted from a transmission optical fiber 1, a nozzle 50 for emitting laser light condensed in the lens barrel unit toward a workpiece, and an assist gas flow path 30 which is provided in the head body and through which assist gas injected together with laser light from the nozzle flows, and between a protective window 26 of the lens barrel unit in the midway of the assist gas flow path and the nozzle 50, a trap mechanism 45 for blocking progression of dust intruded in the head body from the nozzle to the protective window side is provided. The trap mechanism has throttle parts 45b, 45e for locally increasing flow speed, and a retention capturing part 45f capable of capturing dust.