To increase irradiation density of a laser beam on an object to be irradiated and to enhance irradiation efficiency with a simple structure.

The machining head 21 is equipped with a laser beam 23 from a laser light source not shown, a plurality of laser optical fibers 25 arranged annularly, and an optical element 27 for tilting the optical axis of the laser beam from the plurality of laser optical fibers 25. The laser beam 23 is guided by the plurality of laser optical fibers 25, and is tilted mutually in the optical axes by the optical element 27 to form a conical filmy laser beam 11 having a conical hollow part. To the hollow part of the conical filmy laser beam 11, a powder is supplied from a material power feeding device not shown and is perpendicularly dropped by gravity toward a workpiece 5. The powder 3 always passes through the conical filmy laser beam 11 and melts by receiving energy supply from the conical filmy laser beam 11 at a converging part 29, the melted body is deposited on the workpiece 5 to form a clad layer.