PURPOSE: To facilitate the work at the time of operating a production line in a load transferring device for an unmanned carrying vehicle of the production line by making a height of a loading part of the unmanned carrying vehicles to coincide with a height of a station, and providing a load elevating device in the unmanned carrying device to lift a former load once at the time of receiving a new load and fall the formed load on the new one.

CONSTITUTION: Since a height of a loading part 4 of an unmanned carrying vehicle and a height of a station S are made to coincide with each other, a work W on the station S is pushed to the loading part 4 by a rolled R to be transferred, and is moved into the back by a roller 7. Next, hangers 10 are elevated by winding chains 9 to elevate the work W. Next, a next work is pushed to be positioned under the work W similarly. Next, the elevated work W is fallen on the lower work 2 to piled in two stages. Under this condition, they are moved to a next station. With this structure, the work at the time of operating a production line can be facilitated.