To prevent pieces of copper from invading into the suction surface of a chuck table in self-grinding of the chuck table.

In performing self-grinding in which a grinding means 3 is placed close to the chuck table 2 by a driving means while rotating the chuck table 2 and rotating a grinding wheel 33 and the suction surface of the chuck table 2 is brought into contact with a grinding tool 33b to be ground in order to bring the suction surface 20 into parallelism with the grinding surface of the grinding tool 33b, a grinding tool formed with bonding agent except metal bonding agent is used as the grinding tool 33b. Since the grinding tool 33b does not include any metal, any metal does not invade into the suction surface 20 in self-grinding. Further, any metal does not invade into a wafer from the suction surface 20 in grinding the wafer afterward.