PURPOSE: To efficiently and inexpensively produce the large sized and complicatedshaped metal-base composite material without causing the fault such as pore.

CONSTITUTION: Plural members of metal-base composite material are produced by infiltrating and packing the molten metal of aluminum alloy having ≥1wt.% Mg content into the aggregate of a discrete ceramic reinforcement under the atmosphere containing the nitrogen of an atmospheric pressure (stage 1). Then the large sized parts made of the metal base composite material is produced by heating and fusing the plural members of metal-base composite material (stage 2), and casting the fused liq. to a desired parts (stage 3).