PURPOSE: To simplify a structure, regarding a two-story parking machine having a safety mechanism for preventing the natural fall of an upper pallet for loading an automobile.

CONSTITUTION: The first and second links 90 and 91 are coupled to each other approximately in an X-shape, thereby constituting a link mechanism 9 for use to elevate and lower a pallet. Also, a lock leg 80 is suspended from the link extended upward from the turning support point of the link mechanism 9, in such a way as capable of free oscillation. The lower end of the lock leg 80 is kept faced to the upper side of the other link, and a coupling step section 85 is formed on the lower end of the leg 80 where faced to the link. In this case, when the mechanism 9 is at a standing position, the lower end of the section 80 is coupled to the section 85. The link section corresponding to the vicinity of the lower end of the leg 80 is provided with a lock release lever 87. When the link mechanism 9 is made to further stand, the lever 87 causes the oscillation of the leg 80, mechanically interlocked with the mechanism 9, thereby releasing engagement between the leg 80 and the section 85.