PURPOSE: To enable simplification, thinness and high accuracy by engaging a table with one of second movable members by means of a circular projection and a circular hole, and supporting the same to the other secondary movable member by means of circular projection and a slot substantially parallel to the moving axis of a first movable member, both projection and hole being engaged therewith.

CONSTITUTION: An X-axis movable member 2 is supported along a base 1, a nut 6 of the member 2 is threadedly engaged with a screw shaft 5 supported between X-axis support parts 3, and a motor 7 is supported to the support parts 3. A pair of Y-axis movable members 8, 9 are supported on an X-axis movable member 2, nuts 15, 16 of Y-axis movable members 8, 9 are threadedly engaged with screw shafts 13, 14 supported between both sides of the Y-axis support part 10 in the vertical direction with the screw shaft 5, and a motor 17, 18 are supported to the Y-axis support part 10. On both sides of a table 19, a circular hole 22c and a slot 23 parallel to an X-axis are formed, wherein the circular hole is engaged with a circular projection 20, the slot 23 being engaged with a circular projection 21, and the table 19 is supported so as to rotate around the circular projection.