To automatically supply loading slippers and automatically deal with plates even if the length or the width of a plate is changed, when plates transported one by one are stacked in order on a pair of slippers.

This stacking device is provided with a plate transfer machine 3 grasping a panel 1 on a supply conveyor 2, transferring it to a lifter, and stacking it, and a slipper supply machine supplying stacking slippers to the lifter. The plate transfer machine can detect hydraulic pressure of a hydraulic cylinder opening/closing a grasping part 31 so as to control the grasping force of the grasping part 31, and the slipper supply machine is constituted of a carriage 6 drawing out a pair of the loading slippers from a cassette 5 and positioning them at a desired interval, and a slipper push-out machine 7 pushing out the loading slippers from the carriage 6 onto the litter.