PURPOSE: To follow up a leveling device in the control thereof without respect to the rotary speed, by joining the connection part of the vehicle side of an attracting connection arm to the leveling vehicle with a swing axis so as to be freely movable both to the right and left hands and joining the leveling device to this connection part and swinging the connection part of the vehicle side of attracting connection arm by the controller and the swing hydraulic cylinder.

CONSTITUTION: An attracting connection arm 3 is vertically rotated so as to be freely movable up and down against the leveling ground face, taking the axis for vertical movement 5 fitted to a connection part 6 as the supporting point, by the extension and contraction of the hydraulic cylinder 4 for the vertical movement. Next, the connection part 6 is joined to a swing axis 7 vertically fitted to the rear end of a leveling vehicle 1 against the leveling ground face so as to be freely movable. The connection arm 3 and the leveling device 2 at the rear end swing around this supporting point on the leveling ground face. Further, the length of hydraulic cylinder 10 equipped between a fitting axis 8 and a movable axis 9 is variably changed to regulate the motion of leveling device 2 around the connection part 6. In this way, the leveling of the ground surface can be ideally finished without influences of the slope of leveling ground surface of the external forces acting on the leveling device 2 and also without traces of tire belts.