A laser welding method for joining stacked metal foils in which a plurality of copper-based foils are stacked and a tab plate formed of a copper-based material is provided. The laser welding method includes placing one end of the stacked metal foils on the tab plate; and irradiating the one end of the stacked metal foils and the tab plate with a blue laser beam by reciprocating the blue laser beam a plurality of times along a welding line on the tab plate along the one end of the stacked metal foils. The stacked metal foils and the tab plate irradiated with the blue laser beam have a joint portion in which a portion between a surface of the tab plate irradiated with the blue laser beam and the one end of the stacked metal foils is obliquely joined to the surface of the tab plate.