PURPOSE: To sufficiently remove an impurity oxygen in SiC and improve sinterability by arranging deoxygenated members around a formed compact of SiC, temporarily sintering the compact in a vacuum, adsorbing the oxygen in the SiC on the deoxygenated members and carrying out normal sintering.
CONSTITUTION: For example, a formed compact 1 of SiC and formed compacts 2 of aluminum nitride as deoxygenated members surrounding the formed compact 1 so as not to mutually contact are arranged in a sheath 3 made of carbon to carry out temporary sintering at 1650°C in a vacuum. The formed compacts 2 are then removed from the interior of the sheath 3 to perform normal sintering at 2050-2150°C. Thereby, silicon oxide in the SiC is released to the atmosphere by heating in the vacuum, adsorbed on the aluminum nitride and converted into aluminum oxide. Since the SiC raw material is purified to a high purity by releasing of the oxygen, sinterability is improved to enable reduction in the amount of a sintering assistant and sintering temperature. As a result, growth of grains following phase transition at high temperatures is reduced to provide the objective dense and high-strength sintered compact.