PURPOSE: To simplify the structure of a space-setting apparatus for setting the space between raising seedling boxes in a state suitable for greening in the transfer of a group of raising seedling boxes to a greening cart after sprouting.

CONSTITUTION: Each raising seedling box 1 in a group of stacked raising seedling boxes 1 after sprouting is lifted by swinging the right and left lifting claws 15, 15 from the right and the left sides. When the uppermost lifting claw is lifted while fixing the lowermost lifting claw 15, the other lifting claws 15 connected with each other through chains 21 are lifted according to the motion of the uppermost lifting claw 15. Each chain 21 is extended to a definite extension when the uppermost lifting claw 15 reaches a prescribed position. The distance between the lifting claws, i.e., between the raising seedling boxes is set to a level suitable for the greening process by the above-mentioned process.