PURPOSE: To produce a high toughness ceramic composite material consisting of silicon nitride as a matrix and silicon carbide as a reinforcing material with satisfactory reproducibility.

CONSTITUTION: The Al content of a ceramic composite material consisting of silicon nitride as a matrix and silicon carbide as a reinforcing material is regulated to ≤0.3wt.%. At the time of production, the total Al content of silicon nitride and silicon carbide as starting materials is regulated to ≤0.3wt.% and the starting materials are sintered. In the case of >0.3wt.% Al content, a high toughness ceramic composite material is not obtd. with satisfactory reproducibility. For example, Al is removed from the starting materials by acid treatment or other method before use. When a sintering aid is used at the time of sintering, the total Al content of the starting materials and the sintering aid is regulated to ≤0.3wt.%. The silicon carbide as the reinforcing material can be used in the form of spherical particles, platy particles, whiskers, etc.