To efficiently hoist a car body, use space effectively, and streamline work environment, by arranging a lift device which hoists only a car body or both the car body and its truck in a hole which is drilled in a running conveying road of a railway rolling stock equipped with a car body and a truck.

A jack device 4 is equipped with a lift 10 which has a pair of rails 9 fixed to its upper surface, the lift 10 is lifted up and down by four screw shafts 11 fixed to its four corners, first transmission boxes 12 with each screw shaft 11, and three second transmission boxes 14 which transmit power of a motor 13 to each first transmission box 12. Nuts threadedly engaged with the screw shafts 11 are engaged with the first transmission boxes 12 such that it can rotate and cannot move vertically, and rotating of the nut lifts up and down the lift 10. When a vehicle is stopped at jack devices 4 position, and the motor 13 of each jack device 4 is rotated synchronously, the lift 10 synchronously rises and the car body is lifted up together with the truck.