To relax thermal stress between carbon fibers and Al matrix, to prevent the occurrence of peeling in the interface, and to stably obtain low coefficient of thermal expansion and high thermal conductivity by dispersing the carbon fibers, to which ceramic particles of specific particle size in specific amounts are allowed to adhere dispersedly, throughout the Al matrix.

Carbon fibers, where ceramic particles are allowed to adhere dispersedly to the surface, are dispersed throughout Al matrix, by which the high performance Al matrix composite is obtained. At this time, it is preferable that the volume ratio of the ceramic particles among all the materials to be dispersed (carbon and ceramic particles) is regulated to 20-45%. These ceramic particles are SiC particles having 0.5-10 μm average particle size, excellent wettability to Al, and having low coefficient of thermal expansion, and relatively high thermal conductivity. Further, the carbon fibers are composed of graphitic carbon fibers or have crystal structure close to that of graphitic carbon fibers, and have about 10 μm diameter. Moreover, the Al matrix is composed of an Al-Si alloy containing about 12-25% Si and excellent in castability.