To provide a machine tool capable of coping with both a workpiece requiring a small driving force, for example, having good machinability and a workpiece requiring a large driving force, for example, having poor machinability. The machine tool includes a coupling mechanism 9 which couples a first tool post (first tool driving mechanism) 5 and a second tool post (second tool driving mechanism) 6 so that a driving force of the second tool post 6 is added to a driving force of the first tool post 5.