To obtain a structure for brazing a pipe member to a through hole made in the body of a tank for a heat exchanger in which fixing strength is enhanced significantly compared with a conventional one.

A planar reinforcing member 15 is brazed to the pipe fixing face 11c of a tank body 11 and an annular protrusion 15e, projecting from the pipe fixing hole 15d of the reinforcing member 15 to the pipe fixing face 11c side, is inserted into a through hole 11d made through the pipe fixing face 11c. A pipe member 17 is then applied over the annular protrusion 15e and brazed while being pressed.