To provide a device for stacking raising seedling boxes working according to the following procedure: raising up seedling boxes conveyed on a conveyer using a lifting mechanism, stacking the seedling boxes sequentially from the bottom, receiving the lowest-stage seedling box with a locking catch plunged into a stacking passage from the right and left to lock the seedling box so as to improve treating capacity of the device.

This device for stacking raising seedling boxes has the lifting mechanism 5 structured so that right and left two sets of scooping-up members 21 arranged at both sides of a passage for carrying the seedling boxes in the mechanism are rotated around a shaft center moving in a longitudinal direction so as to be synchronous to each other in a reverse direction so that a seedling box (w) is scooped up using the right and left scooping-up members. Respective scooping-up members 21 are each provided with a convex curved surface Sa having a small curvature and abutting to the bottom of the seedling box (w), and a box sliding-down guide surface Sb is connectedly attached to the convex curved surface Sa at the upper side in the rotational direction over a predetermined length.