PROBLEM TO BE SOLVED: To produce a ceramic fiber/SiC composite material having a low void ratio and capable of manifesting excellent high-temperature characteristics.
SOLUTION: A formed compact of SiC fibers or C fibers is pressurized under 1-3 MPa and the resultant fiber formed product in a pressurized state is then permeated with an alkylchlorosilane. The mutually adjacent SiC fibers or C fibers are bonded with an SiC phase produced by a thermal decomposing reaction of the alkylchlorosilane and the fiber formed product is subsequently released from the pressurized state. The SiC phase is further deposited on the interior of the fiber formed product by the thermal decomposing reaction of the alkylchlorosilane. The alkylchlorosilane is thermally decomposed to deposit the SiC phase by heating and maintaining the fiber formed product at 900-1,200°C. The SiC phase is deposited in two stages of the pressurized state and the released state of the pressurization to thereby uniformly fill internal voids of the fiber formed product with the matrix of the SiC phase. Thereby, a composite material having a high degree of denseness is obtained.