Provided is a machine tool which is equipped with a floating mechanism, and the whole of which can be miniaturized and lightened, the floating mechanism being equipped with carriers of loads generated in both radial and thrust directions, resulting in deformation of the floating mechanism being reduced. The floating section (4) of the machine tool is provided with a hollow circular-plate-shaped inner ring (9) comprising an outer peripheral surface section (9a), an upper surface section (9b), and a bottom surface section (9c); and an outer ring (8) comprising an inner peripheral section (8a) and an inner ring receiving section (8b). The outer ring (8) is fixed to a robot arm. The inner ring (9) is fixed to a tool driving section. The outer peripheral surface of the inner ring (9) is formed by a spherical surface which is equidistant from the center point (14) of a hollow circular plate.