A multiply-wound tube includes: a tube body formed by winding, into a roll, a metal plate comprising a core material layer made of a first metal material and a brazing material layer made of a second metal material having a lower melting point than the core material layer; and a joint portion that is formed at a portion of the metal plate that is wound in layers, wherein the portion of the metal plate that is wound in layers is brazed together by the brazing material layer being melted by heat from a laser projected onto the tube body.