To provide a seedling box stacking device solving the problems that increase in a lifting speed in view of work efficiency brings a result that seedbed soil and/or seeds in a seedling box are/is one-sided due to stopping impact when stopped at an upper place and thereby causes later difficulty in germination and seedling growth because seedling boxes are successively lifted one by one in the upper direction of a conveyer at a seedling box lifting part at a fixed speed, or inversely decrease in the lifting speed to prevent the seedbed soil or seed in the seedling box from being one-sided results in lowering of work efficiency.

This seedling box stacking device functions as follows: successively lifting every predetermined number of a plurality of seedling boxes C carried with a seedling box-transferring conveyer 12 at the seedling box-lifting part, and stacking them in a plurality of layers. In the device, the lifting speed just before finishing lifting operation is made lower than an initial lifting speed at the seedling box lifting part.