PURPOSE: To provide a high-density sintered body by heating a body composed of silicon carbide and a boron-containing material to an effective sintering temperature in the presence of nitrogen, removing the nitrogen down to have a pressure of less than 10-2 mbar by evacuation, and next continuing sintering under vacuum or in the presence of the inert gas other than nitrogen.

CONSTITUTION: Concerning the method for sintering a body composed of silicon carbide and a boron-containing material, the body is heated to an effective sintering temperature in the presence of nitrogen, the nitrogen is removed to have a pressure less than 10-2 mbar by evacuation and next, sintering is continued under vacuum or in the presence of an inert gas other than nitrogen. As a sintering temperature for this method, temperatures within the range of about from 1700 to 2500°C are used. Besides, as the inert gas other than nitrogen, argon is appropriate. Next, the body to be sintered can be contain the boron- containing material in about 0.1 to 2 wt.% in calculation as element boron and can contain the boron-containing material in 40 wt.% at a maximum as well.