A silicon carbide single crystal of extremely wide application fields including the semiconductor field; and a method of etching a silicon carbide single crystal in which nitrogen trifluoride plasma is applied to the silicon carbide single crystal to thereby smooth the same. For obtaining a silicon carbide single crystal whose smoothness (surface roughness) falls within +- 150 nm or relevant material, a gas containing nitrogen trifluoride is plasma-excited so as to smooth the surface of the silicon carbide single crystal. It is preferred that the pressure of nitrogen trifluoride gas be in the range of 0.5 to 10 Pa. Further, it is preferred that the flow rate of nitrogen trifluoride gas be in the range of 5 to 15 sccm.