PURPOSE: To facilitate loading/unloading work of a load and lifting operation of a load deck by raising the deck automatically to a prescribed position after the load on the load deck is unloaded, and lowering the deck automatically to a prescribed position after the load is loaded onto the load deck.

CONSTITUTION: After a load positioned on the top stage is unloaded during rainsing up a load deck 5 for replacing the load positioned on the load deck 5 onto a rack, the load 5 is controlled to be raised up until a sensor 11 detects the load at the next stage through a raising control means B. On the other hand when the load on the rack is placed onto the load deck 5, the load 5 is lowered until the sensor 11 can not detect the load by a lowering control means C to complete loading work with the load deck kept at one stage lower than the previous stage. When the load is placed onto the rack, the load deck 5 is lowered until the sensor 11 can not detect the load. Thus loading/unloading work is carried out. It is thus possible to carry out loading/ unloading work of load and lifting operation of the load deck 5 easily.