To increase the hardness and reduce the weight by constituting a grinding wheel base from a Si-SiC composite material or SiC composite material.

This grinding wheel base 21 is formed of a Si-SiC composite material or SiC composite material. Since the Si-SiC composite material and SiC composite material are lighter in weight than aluminum, the energy quantity required for rotation of a grinding wheel 20 can be minimized in the use as the material of the grinding wheel base 21 to reduce the cost required for grinding. Further, since the Si-SiC composite material and SiC composite material are superior in hardness to iron, the biting speed of abrasive grains 22 to the grinding wheel base 21 can be delayed in the use as the grinding wheel base 21 to extend the life of the grinding wheel 20. Since the grinding wheel 20 can be rotated with a small quantity of energy without causing the biting of the abrasive grains 22, a high-speed rotation can be performed to improve the efficiency of grinding work.