Abstract: A numerical control machine comprises a headstock rotatably supporting a spindle for a workpiece and a tool rest assembly in front of the headstock. The tool rest assembly includes a first pair of tool rests which are disposed on both sides of the longitudinal axis of the headstock spindle and are simultaneously movable in a first direction perpendicular to the spindle axis, and a second tool rest which is movable in both second and third directions perpendicular to the spindle axis. Either the headstock or the tool rest assembly is movable in a fourth direction along the spindle axis. The movement of the first pair of tool rests in the first direction, the movement of the second tool rest in the second and third directions, and the movement of either the headstock or the tool rest assembly in the fourth direction are carried out under the control of a numerical control unit.