PURPOSE: To obtain a high-performance minute rotating stage with little accuracy deterioration by bringing one end of each leg member the other end of which is installed on the end of each actuator into contact with the slip plate inside a base body while installing an actuator between the leg members.

CONSTITUTION: First, as an actuator 4 is contracted, a leg member 5 is lifted up from a slip plate 10 and then, an actuator 8 is contracted moving the leg member 5 downward. Then, the actuator 4 is extended and the leg member 5 is placed onto the slip plate 10. Next, an actuator 6 is contracted lifting up a leg member 7 from the slip plate 10 and then the actuator 8 is extended and the leg member 7 is moved downward. Then, the actuator 6 is extended to place the leg member 7 onto the slip plate 10, thereby completing one cycle. In this case, the leg members 5, 7 are moved downward by the extending/ contracting amount of the actuator 8 and a free movable body 3 is minutely rotated clockwise with O as the center by that amount. Thereby, the rotating angle of the free movable body 3 can be freely adjusted.