A heat exchanger (100) is provided with a channel forming body (11) and a serpentine pipe unit (13). The channel forming body (11) has a serpentine first channel (19) through which first fluid is caused to flow. The serpentine pipe unit (13) has a second channel (20) through which second fluid is caused to flow, and the serpentine pipe unit (13) is disposed in the first channel (19) of the channel forming body (11). At least a part of the channel forming body (11) is configured from a resin foam body. The channel forming body (11) has, for example: a plate-shaped upper member (15) having a groove which serpentines in a plane; and a plate-shaped lower member (15) combined with the upper member (15). The lower member (15) covers a groove (16) in the upper member (15) to form the first channel (19).