Patent attributes
A first laser working method includes a step of irradiating the metallic work held by a rotation holding mechanism, with a nanosecond laser beam from a first laser oscillation mechanism, to form a through hole, and a step of irradiating, when the metallic work is rotated under the action of the rotation holding mechanism, the inner wall of the through hole with a picosecond laser beam from a second laser oscillation mechanism, thereby to finish the same. While forming the through hole, metal vapor is sucked from the outside of the metallic work. Then, the gas is fed from the outside of the metallic work, and the inside of the metallic work is suctioned. In a second laser working method, when a lower hole made through is radially enlarged, the exit side of the lower hole is kept lower in pressure than the laser incident (or entrance) side.