An NC machine tool system includes an NC machine tool (10), a first operation panel (22) and a second operation panel (24) for the NC machine tool, a multi-joint robot (40), a memory (450), and a robot controller (50). The multi-joint robot (40) is disposed above the NC machine tool. The memory (450) stores a wait position return program by which the multi-joint robot (40) is operated. The robot controller (50) controls the multi-joint robot (40) in accordance with the program. Operation panels (22, 24) are respectively provided with switch keys (22c, 24c) operated to execute the wait position return program stored in the memory (450) so as to operate the multi-joint robot (40).