There is provided a machine tool which holds a large number of tools and capable of performing various kinds of works without replacing the tools, which is easy to operate and which allows faster and accurate operations with less number of movable parts. A front tool post (141) and a back spindle (120) are configured to be integrally movable in a Y-axis direction, and a plurality of front working tools (140) and a plurality of back working tools (130) are disposed on the front and back tool posts (141) and (131), respectively, in a plurality of tiers in the Y-axis direction.