An object of the present invention is to provide a polishing apparatus which is capable of configuring a surface of a polishing tool without damaging the polishing tool. In order to solve the above-mentioned problem, the present invention provide a rotary machining apparatus comprising a polishing tool for polishing a sample; a rotary disk for holding the polishing tool; a tool for configuring a surface of the polishing tool; and a position adjusting mechanism for adjusting a gap between the tool and the polishing tool, which comprises a rotating mechanism for rotating the tool; and a sensor for sensing a change in the rotation of the rotating mechanism, a height at starting to configure the polishing tool using the tool being determined based on the change in the rotation obtained by the sensor.