PURPOSE: To obtain a composite material excellent in ductility, fracture toughness and crack propagation resistance by specifying the ratio and shape of composite material regions in a matrix and the fraction of a reinforcing material contained in the composite material regions.

CONSTITUTION: This metal-based composite material has a structure contg. plural lump-shaped composite material regions dispersed and mixed in a matrix metal as a simple substance. The region of the matrix metal is 10-95vol.% of the entire material and the vol. fraction of a reinforcing material contained in the composite material regions is 10-95%. The number of the composite material regions is preferably ≥10 per unit vol. (cm3) and the vol. fraction of the reinforcing material in the matrix metal is preferably ≤1/3 of that in the entire material. This metal-based composite material is preferably produced as follows; A slurry contg. SiC whiskers and borate glass is spray-dried, the resultant powder is formed into a preform and a molten Al alloy is allowed to penetrate into the preform and solidified.