A main spindle and a back spindle grip works W, respectively. Or, the main spindle grips one end of a work W and the back spindle grips the other end of the work W. A tool is attached to a tool spindle. By adjusting the positions of the spindles and the position of the tool spindle, the work W gripped by the main spindle and the back spindle is machined by the tool. Since tool spindle can change the direction of the tool, the work W, including both ends thereof, can be entirely machined into a complex shape. A guide bush supports the work W to prevent the work W from being bent when a lengthy work W is machined. Therefore, this lathe can entirely machine a long or short work into a complex shape.