PURPOSE: To grind a probe during the measurement of a wafer, by independently providing a wafer chuck part and a probe grinding part in the stage part of a prober.

CONSTITUTION: The upper part of the stage part 1 of a prober is enlarged and a probe grinding part 2 is provided so as to be adjacent to the wafer chuck part 4 of the stage part 1. Herein, it is necessary to set the thickness of the probe grinding part 2 composed of a ceramic material to difference of ±50μm or less as compared with that of a wafer 3. Then, the probe 5a of a probe card 5 is brought into contact with the wafer 3 sucked by the wafer chuck part 4 of the stage part 1 and the device on the wafer 3 is inspected in a wafer state. During this inspection process, the grinding of the probe 5a of the probe card 5 can be adequately performed by the probe grinding part 2.