To sufficiently exhibit ability of an apparatus for stacking raising seedling boxes by devising a supply and carrying-out structure of an installation table.

Nursery boxes conveyed are lifted up and successively stacked from the lower box and a stacked nursery box group having prescribed box numbers is collected and loaded on the installation table having wheels and the installation table T is conveyed to a transferring position and transferred onto a waiting and conveying carriage. The installation table T in the lowest stage among a plurality of installation tables stacked on a fixed supporting frame 75 is fixed by a fixing part 80 attached to a conveying chain 77 and conveyed along above the supporting frame 75, and horizontally long rail members 78 and 79 receiving and supporting wheels 73 of the installation table T removed from the supporting frame 75 by being fixed and conveyed so as to enable rolling transfer of the wheels 73 in horizontal direction perpendicular to a box-conveying direction are horizontally laid and attached to a conveying chain 77.