PURPOSE: To reduce power consumption while making an outer shape small by driving both X, Y shafts with one motor by use of splines and gears and optionally selecting a driving shaft by switching over clutches.

CONSTITUTION: The rotation driving force of a motor 1 is transmitted to an X-axis screw 4 by engaging a first clutch 7 and an X table 8 on which an X-axis nut is fixed is moved in the direction parallel to the X-axis screw 4 by means of X-axis rails 10. Then, as the clutch 7 is disengaged while engaging a second clutch 15, the driving force of the motor 1 which is transmitted from a gear 3 to a gear 11 is transmitted to a spline shaft 12. Further, a spline nut 16 joined to the shaft 12 is rotational and its turning force is transmitted to a Y-axis nut 18 with its direction being changed at a right angle via gears 17 and 19. Thereby, a Y table 20 to which a Y-axis screw is fixed is moved on the X table 8 in a direction at a right angle to the X-axis screw 4 being guided by Y-axis rails 22. As a result, the number of motors and their control circuits can be reduced thus reducing power consumption.