PURPOSE: To obtain a whisker preform always having excellent properties and structure by injection molding a kneaded material of ceramic whiskers and an organic binder into a split mold constructed of a cellular material, heating the aforementioned injection molded body directly in a split mold and subjecting the resultant molded body to degreasing treatment.

CONSTITUTION: A kneaded material containing 5-30vol.% ceramic whiskers and 70-95vol.% organic binder is injection molded into a split mold constructed of a cellular material. For example, SiC whiskers are preferred as the above- mentioned whiskers and, e.g. paraffin wax having <100°C softening point is preferred as the organic binder. The aforementioned kneaded material is then normally granulated into pellets for molding and subsequently injection molded into the split mold in the form of the final preform constructed of the cellular material. The injection molded body directly in the split mold is then melted by setting a heating rate of ≤10°C/hr to absorb a prescribed amount of the binder component in the cellular structure in the mold and the temperature is finally kept at about 500°C to thermally decompose all the binder and carry out degreasing treatment. Thereby, the objective whisker preform is obtained.