PROBLEM TO BE SOLVED: To stably insert or remove a seedling box into or out of a shelf member of a seedling box-storing shelf. SOLUTION: Shelf members 36 of upper and lower many layers, capable of holding seedling boxes so as to be freely inserted and removed are installed in a shelf frame 35 so as to be freely lifted and lowered. The shelf members 36 adjacent to each other in the upper and lower direction are connected so that the distance in the upper and lower direction may be freely expanded and contracted, and a lifting and lowering structure 41 for lifting and lowering the topmost shelf member 36 is installed in the shelf frame 35.