A silicon carbide sintered body according to the present invention is a silicon carbide sintered body having a density of 2.9 g/cm.sup.3 or higher, obtained by means of hot pressing a mixture of silicon carbide powder and a non-metal-based sintering additive such as an organic compound which produces carbon upon heating at a temperature of 2,000.degree. C. to 2,400.degree. C. and under a pressure of 300 to 700 kgf/cm.sup.2 in a non-oxidizing atmosphere. It is preferable that the silicon carbide powder have an average particle diameter of from 0.01 to 10 .mu.m and that the non-metal sintering additive be a resol type phenol resin. The present invention is to provide a silicon carbide sintered body of high quality which has a high density, a high purity, and a high electrical conductivity and which is useful for semiconductor manufacturing industry.