According to this brazing method, a first base member having a non-plated surface, a metal layer for functioning as a diffusion barrier layer, a brazing foil, and a second base member having a surface are arranged in this order so that the non-plated surface of the first base member and the surface of the second base member are faced with each other. The first base member and the second base member are brazed by using the brazing foil. The cost of providing a diffusion barrier layer between the first base member and the brazing foil is thereby reduced.