Abstract: A heat exchanger, characterized in that Al or Al alloy tubes, each having a thermally Zn-sprayed layer formed on the surface of it, and having a brazing filler metal layer formed on said thermally Zn-sprayed layer using a powdery brazing filler Al alloy composed of 5 to 60 weight % of Si and the balance of Al and unavoidable impurities, are combined with and brazed to an Al or Al alloy header having a brazing filler metal layer formed using a powdery brazing filler Al alloy composed of 5 to 60 weight % of Si and the balance of Al and unavoidable impurities. The tubes and the header are strongly bonded to each other, and Zn is uniformly diffused and distributed. So, the heat exchanger shows good corrosion resistance.