The invention provides a composite working lathe capable of improving the efficiency of workpiece machining area by arranging a workpiece handling device below a spindle of the composite working lathe. The composite working lathe 1 comprises a spindle 20 and a tool spindle 30 on a bed 10. A workpiece handling device 40 arranged below the spindle 20 can be moved along a W axis parallel to the axis line C1 of the spindle. The workpiece handling device 40 has a workpiece handling head 50 that pivots in the direction of arrow F around an axis line C2, and grips the workpiece K1 via a gripper 60. The axis line C2 is an axis perpendicular to the vertical plane including the axis line C1 of the spindle 20, and the workpiece handling head 50 is raised for 90 degrees when the gripper 60 receives the workpiece K1 from the spindle 20. The angular position of the workpiece handling head 50 is allocated and the workpiece K1 is machined via a tool T1 on the tool spindle 30.