To provide a method for grinding a silicon carbide crystal substrate with a high-precision and stable surface without processing stain and lack.

This method has been devised to grind a silicon carbide crystal substrate. It contains a process where the grinding liquid (7) with the abrasive particles made of boron carbide is used to grind the silicon carbide crystal substrate (2) with a surface roughness Rz of 50 μm or less. In this way, the diamond used so far as an abrasive particle is replaced with the boron carbide so that damage to the materials to be polished such as the silicon carbide crystal and grind stool can be reduced and the surface can be ground with precision.