A machine tool comprises a main spindle, a tool post body provided with a first tool mounting part and a second tool mounting part facing each other with a workpiece inbetween in a predetermined facing direction, and a tool post body driving unit for moving the tool post body in at least the facing direction. The tool post body comprises a first tool post unit provided with the first tool mounting part, a second tool post unit provided with a portion of the second tool mounting part with a relative interval with respect to the first tool post unit in the facing direction kept constant, a third tool post unit provided with the remaining portion of the second tool mounting part with a relative interval kept variable; and a relatively-driving unit for moving the third tool post unit in the facing direction with respect to the first tool post unit.

A machine tool comprises a main spindle, a tool post body provided with a first tool mounting part and a second tool mounting part facing each other with a workpiece inbetween in a predetermined facing direction, and a tool post body driving unit for moving the tool post body in at least the facing direction. The tool post body comprises a first tool post unit provided with the first tool mounting part, a second tool post unit provided with a portion of the second tool mounting part with a relative interval with respect to the first tool post unit in the facing direction kept constant, a third tool post unit provided with the remaining portion of the second tool mounting part with a relative interval kept variable; and a relatively-driving unit for moving the third tool post unit in the facing direction with respect to the first tool post unit.