rotates with respect to a fixed screw shaft also a hollow part air suction holes sensor grooves and bolt grooves etc are formed in the support frame of the second slider support part 16 as in the support frame 24 in the first slider support part 12 during driving that is when the first slider 14 is being moved reciprocally by the motor proper 46 the hollow parts 52b 52d of the support frame 24 are air sucked by the pump 55 as a result of this air suction at the contacting parts of the guide part 44 of the first slider 14 and the guide rail 28 produced dust and the like is sucked into the hollow parts 52b 52d through the air suction holes 54 similarly in the second slider support part 16 also localized suction of produced dust and the like is carried out at the guide rail part of the second slider 18 through air suction holes formed in the support frame as a result produced dust and the like does not get outside through the window w and impairment of the cleanliness factor is prevented as described above in this embodiment because localized suction of the insides of the first slider support part 12 and the second slider support part 16 is carried out using the hollow parts formed in the support frame 24 compared to a case wherein pipes are disposed as conventionally the first slider support part 12 and the second slider support part 16 and so on can be made small that is it is possible to.