A composite material includes an SiC porous ceramic sintered body, which is formed 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. A copper alloy impregnating the porous ceramic sintered body includes 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 include 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 contain unavoidable impurities and gas components.