<p>Machining conditions in float polishing method have been determined empirically and there is a need to elucidate the levitation principle of the workpiece and to propose a theoretical method to determine the machining conditions. In this research, the levitation quantity of the workpiece was measured by the displacement sensor and found to be about 4 µm. The order of this value agreed with the prediction in the literature. From the FEM simulation of the thin film fluid based on the Reynolds equation, it was predicted that the pressure distribution under the workpiece was non-uniform and cavitation was generated.</p>