To perform the operation of placing a workpiece on a table with satisfactory working efficiency, and to highly accurately machine a workpiece overhung part overhung from the table while preventing chattering vibration.

A machine tool includes: a table 3 on which a workpiece 2 is placed; a clamp device 5 which is arranged at the front side of the table 3; and tools 6 and the like which are arranged at the front side of the table 3 to perform machining such as chamfering on the workpiece 2. The clamp device 5 is equipped with upper and lower clamping pieces 10, 11 that vertically clamp the overhung part 9 of the workpiece 2 overhung from the front edge 28 of the table 3, and placed on the upper face 15 of the table 3. In a workpiece clamped state so that the overhung part 9 is clamped by the upper and lower clamping pieces 10, 11, the tools 6 perform machining on a part 13 to be machined which constitutes the front side of the clamped part of the workpiece 2.