A controller of a machine tool acquires coordinates of a first machining start point of an eccentric shape in a reference phase of a workpiece around a spindle axis, a second machining start point in an anti-phase, a first machining end point in the reference phase, and a second machining end point in the anti-phase. The controller decides a moving path of the tool in association with rotation of the workpiece at least according to the coordinates of the first start point, the second start point, the first end point, and the second end point to form the eccentric shape around an eccentric axis passing a start point origin between the first start point and the second start point and an end point origin between the first end point and the second end point and thereby controls movement of the tool in association with rotation of the workpiece.