A method for machining a workpiece in which a machine tool comprising a first and a second chuck devices is employed to machine the workpiece, the machine tool being used in which the first and the second chuck devices comprise a chuck main body, plural chuck jaws, a chuck jaw drive body, and a pressing member, the method comprising: machining a clamp part of the other end part of the workpiece in a state where one end part of the workpiece is clamped by the first chuck device; machining a clamp part of the one end part of the workpiece in a state where the clamp part of the other end part of the workpiece is clamped by the second chuck device; and executing desired machining on the workpiece in a state where each of the clamp parts are clamped by each of the chuck devices.