PROBLEM TO BE SOLVED: To prevent a seedling box fed with feed rollers from vigorously dropping and making strong collision with the preceding underlying seedling box. SOLUTION: A seeding transplanter 10 is designed to place a seedling box N provided with hole parts Nc at a regular interval in an edge part Nb parallel to the feeding direction in a seedling feeding part 14 continuous to the upper part of a seedling-carrying platform 13, feed the seedling box N to a seedling pushout apparatus 12 located under the seedling-carrying platform 13 and push out the seedlings from the seedling box N with the seedling pushout apparatus 12. In the seedling transplanter 10, feed rollers 15 having a plurality of protruding parts 15a engaging with the hole parts Nc of the seedling box N in the bottom part 14a of the seedling feeding part 14 on the periphery are provided and the feed rollers 15 are driven and rotated with a motor 17. A first detector 18 for detecting the presence or absence of the seedling box N is installed at the lower end position of the seedling box N in a state of the hole parts Nc on the top side of the seedling box N engaging with the protruding parts 15a of the feeding rollers 15. The motor 17 is stopped in a stage of detecting the presence of the seedling box N with the first detector 18. The seedling box N is fed at a low velocity by inertia with the feed rollers 15. COPYRIGHT: (C)2004,JPO&NCIPI