A composite material has SiC produced by preliminarily sintering a porous body having a coefficient of thermal expansion lower than the coefficient of thermal expansion of copper to construct a network therein, the SiC being impregnated with a copper alloy. The copper alloy comprises copper and one or more additive elements which are prepared to impart a coefficient of thermal conductivity of 160 W/mK or higher to the composite material. The additive elements comprise up to 5% of at least one element selected from Be, Al, Si, Mg, Ti, Ni, Bi, Te, Zn, Pb, Sn, and mish metal, and also contains unavoidable impurities and gas components.