A welded metal component, includes: a first component; a second component that is stacked on the first component and that is made of a material different from the first component; and at least one welded part that passes through the second component so as to reach the first component, wherein a proportion of an intermetallic compound present in the at least one welded part is from 15% to 60%, and the intermetallic compound includes a metal element that constitutes the first component, and a metal element that constitutes the second component. Further disclosed is a battery comprising the above welded metal component, wherein the second component serves as a bus bar, and the first component serves as an electrode for the battery.