To provide the structure of a heat exchanger being suitable for the cooling device of an intercooler, a radiator, and a semiconductor circuit by constituting it using the porous metal member of a gas passage, by increasing a heat transfer area, and improving heat exchange efficiency.

In a heat exchanger, a porous metal member 1 consisting of a metal material with a high heat conductivity of aluminum for constituting an air passage 4 for allowing intake air IA to pass and its alloy is arranged, a heat transfer area is largely formed. The porous metal member 1 is arranged while a pipe 2 where a coolant flows penetrates the porous metal member 1. In the porous metal member 1, a metal material with a melt point that is lower than that of a salt core is formed into a porous structure by the salt core being formed by filling into the clearance of porous urethane foam.