To provide a stacking and cargo arrival system for stacking a tray whereon a sample is stored while avoiding load collapsing, and arranging the tray on a conveyer sequentially from the tray at a lower stage by vertically moving the stacked trays while keeping them horizontal in order to avoid load collapsing.

In addition to a vertical movement mechanism, a synchronizing movement means by a rack and a gear for equally maintaining a height position of right and left pressurizing arms for holding the tray is formed with respect to a pair of perpendicularly moving bodies so as to move them perpendicularly.