PURPOSE: To enhance the selecting/receiving operation efficiency for flexible disks the quality of which is sorted by a collective examination apparatus.

CONSTITUTION: A flexible disk stacker mechanism comprises four timing belts 65 for making vertical circulating movements through drive of driving mechanisms 66 controlled by a control circuit 67, and supporting pawls 68 mounted on each timing belt at suitable intervals, each supporting a corresponding one corner of the dropped flexible disk, and stacking the flexible disks for each prescribed number thereof, the supporting pawls being disposed at the position where the flexible disks 4 are allowed to drop. Accordingly, no need exists to interrupt the selecting/receiving operation, and the flexible disks 4 are stacked for each prescribed number thereof. Thus, the selecting, receiving, and processing time length is shortened in corresponding relation to the collective examination apparatus whose examining capability is increased.