In a laser welding method, a gap between first and second members to be welded is made at most 300 μm by pressing the second member against the first member with claws that are pressing parts of a laser welding jig, and the second member to be welded at a place between the claws is irradiated by laser light to laser-weld the first member and the second member. In a semiconductor device, the gap between the first member and the second member at the portion of laser-welding is at most 300 μm.