A crankshaft miller comprising: a first chuck configured to hold a first end portion of a workpiece, the first chuck having a longitudinal datum seat for the workpiece; a second chuck configured to hold a second end portion of the workpiece, the second chuck facing the first chuck; a first servomotor configured to rotationally drive the first chuck; a second servomotor configured to rotationally drive the second chuck; a cutting tool for cutting the workpiece; a synchronous control unit configured to set one servomotor of the first servomotor and the second servomotor as a master motor and the other servomotor as a slave motor and execute a synchronous control of the first servomotor and the second servomotor during cutting the workpiece by the cutting tool; a torque control unit configured to execute a torque control to reduce a reaction torque between the first servomotor and the second servomotor by rotating the slave motor after the synchronous control; and characterised in that: a position adjustment unit configured to adjust rotation positions of the first chuck and the second chuck after the torque control, the position adjustment unit configured to hold the rotation positions of the first chuck and the second chuck when the first servomotor is the slave motor, and the position adjustment unit configured to return the rotation position of the second chuck to a rotation position prior to commencement of the torque control when the second servomotor is the slave motor. a first chuck configured to hold a first end portion of a workpiece, the first chuck having a longitudinal datum seat for the workpiece; a second chuck configured to hold a second end portion of the workpiece, the second chuck facing the first chuck; a first servomotor configured to rotationally drive the first chuck; a second servomotor configured to rotationally drive the second chuck; a cutting tool for cutting the workpiece; a synchronous control unit configured to set one servomotor of the first servomotor and the second servomotor as a master motor and the other servomotor as a slave motor and execute a synchronous control of the first servomotor and the second servomotor during cutting the workpiece by the cutting tool; a torque control unit configured to execute a torque control to reduce a reaction torque between the first servomotor and the second servomotor by rotating the slave motor after the synchronous control; and characterised in that: a position adjustment unit configured to adjust rotation positions of the first chuck and the second chuck after the torque control, the position adjustment unit configured to hold the rotation positions of the first chuck and the second chuck when the first servomotor is the slave motor, and the position adjustment unit configured to return the rotation position of the second chuck to a rotation position prior to commencement of the torque control when the second servomotor is the slave motor. a position adjustment unit configured to adjust rotation positions of the first chuck and the second chuck after the torque control, the position adjustment unit configured to hold the rotation positions of the first chuck and the second chuck when the first servomotor is the slave motor, and the position adjustment unit configured to return the rotation position of the second chuck to a rotation position prior to commencement of the torque control when the second servomotor is the slave motor.