A manufacturing method for a joint body having a first metal member and a second metal member joined together by causing a laser oscillation system to irradiate a surface of the second metal member placed on the first metal member with laser light to form a joint portion including a welded portion where the first metal member and the second metal member are joined together includes continuously supplying the second metal member while pressing the second metal member against the first metal member, the second metal member being a hoop material, and causing the laser oscillation system to emit the laser light.