To eliminate the stagnation of water between fins and the flange of a bottom plate to permit smooth draining by a method wherein a notched part is provided at the lower outside end of fins for a heat exchanger, which are located near the flange of the bottom plate.

A fin is provided with a plurality of holes 10 for penetrated refrigerant pipes as well as cut-and-raised parts 11 while a notched part 12, for increasing a gap between a flange 2a, is formed at the lower outside end of the fin. The notched part 12 is formed at a height same as that of the flange 2a of the bottom plate 2 substantially while the configuration of the notched part 12 is a vertically long rectangular shape, a triangular shape, produced by cutting in a shape of a triangle having on the lower end of the fin 8 as the bottom side, or a cut, produced by cutting largely from the lower end of the fin 8 to the central part of the same. According to this method, the stagnation of water between the fin 8 and the flange 2a of the bottom plate 2 can be eliminated and smooth draining can be effected whereby a heat exchanger can be protected from being iced.