To suppress loss in pressure loss by fully large increasing the sectional area of a channel, and to prevent internal leakages due to brazing faults.

The heat exchanger comprises a first channel plate 8, obtained by drawing a plate-like material and integrated with the outer surface of an end plate 2. Thus, a channel for allowing a heat exchange medium which flows out and flows in from one tank via an opening to flow, is formed. Furthermore, the exchanger further comprises a second channel plate, obtained by drawing the plate-like material and integrated with the outer surface of the plate 8. Thus, a channel for allowing the heat exchange medium, which flow out and flow sin from other tank via the communicating part and other opening of the plate 8 to flow, is formed.