Silicon carbide single crystal is prepared. Using the silicon carbide single crystal as a material, a silicon carbide substrate having a first face and a second face located at a side opposite to the first face is formed. In the formation of the silicon carbide substrate, a first processed damage layer and a second processed damage layer are formed at the first face and second face, respectively. The first face is polished such that at least a portion of the first processed damage layer is removed and the surface roughness of the first face becomes less than or equal to 5 nm. At least a portion of the second processed damage layer is removed while maintaining the surface roughness of the second plane greater than or equal to 10 nm.