A heat exchanger includes an auxiliary heat exchanger, which has plate-shaped first fins and a plurality of first heat transfer tubes, and a main heat exchanger which has plate-shaped second fins and a plurality of second heat transfer tubes. A plurality of burrs are present at specified intervals on edges of the first fins. The auxiliary heat exchanger and the main heat exchanger are so positioned that the edges of the first fins on which the burrs are present are in contact with edges of the second fins, and the edges having the burrs present thereon are positioned on the inner side.