To improve the working efficiency by effectively utilizing the space by mounting a moving dolly which moves in a longitudinal direction of a vehicle at a side of the vehicle to be maintained, and mounting a support body for the wheels of the vehicle to be maintained, movably in a vertical direction on a moving body comprising the rear wheels rotating on the moving dolly in a crosswise direction and the front wheels rotating on a floor surface.

A moving dolly 4 comprises a base body 4a and the rollers 4c, 4d pivotted on a lower face of both side parts of the base body 4a, and the roller 4c is engaged with a guide rail 3a to be moved in a longitudinal direction. Further the rear wheels 6d respectively rotated on the both side parts 4b, are pivotted on the rear parts of the moving body 5, and the front wheels 6a rotating on a floor surface 1, are pivotted on the front parts of the moving body 5. Further a support body 7 comprising a pair of support rollers is pivotted on an upper end of an elevating means 8. The moving dolly 4 is moved along the rail 3 at a position opposite to the wheel A of the vehicle to be maintained. Then a lift fork jack 8a is operated to rise the support roller 7 by the elevating means 8, and the moving body 5 on which the demounted wheel A is placed, is moved backward.