To provide a structure for preventing a spatter generated at a processing part from entering a nozzle part and adhering to a protective glass in a laser processing head.

This laser processing head 1 comprises a light condensing lens 20 and a protective glass 30 in a lens holder 10. An assist gas guide device 50 is installed inside a nozzle part 12, and guides the assist gas supplied in a tangent direction against the nozzle part 12 through a spiral-shaped gas flow path 52 so as to generate the swing flow. The swing flow of an assist gas G1 wipes off the spatter generated at a processing part W1, so as to prevent the adhesion to the protective lens 30.