To simplify the structure of a device itself and reduce cost of that, by using a hydraulic cylinder, a wire, a guide sheave and the like, each of which has relatively simple structure, for a mechanism that moves up/down a pair of right and left gondolas alternately.

The mechanism includes a pair of right and left gondolas 5, a communicating tube 6, a pair of right and left hydraulic cylinders 7, rods 7a, guide sheaves 8, wires 9, a flow rate control valve 10. The pair of right and left gondolas 5 are placed on an escape passage 3 in a building 1 having several stories, so that the gondolas 5 can move up and down between the upper floor position and the lower floor position. Each of the gondolas 5 can accommodate an evacuee who needs care by a caregiver, together with the caregiver and a wheel chair or stretcher. The pair of right and left hydraulic cylinders 7 are placed at the lower floor position in a manner that they stand uprisingly. Each of the cylinders 7 is connected by the communicating tube 6 so that they communicate with each other, and extends and shrinks alternately. Each guide sheave 8 is placed turnably on the upper end portion of a rod 7a of each of the hydraulic cylinders 7. Each wire 9 is hung around each of the guide sheaves 8 and its both ends are connected to the gondola 5 and the hydraulic cylinder 7. The flow rate control valve 10 is inserted in the middle of the communicating tube 6 and the valve 10 controls the flow rate of the hydraulic oil. In case of an emergency escape, from a fire or the like, the right and left gondolas 5 are moved up and down alternately via the hydraulic cylinders 7, the wires 9 and the guide sheaves 8.