To provide a seedling planting device capable of folding a slide plate on an outermost side part relatively easily, while avoiding interference to other members.SOLUTION: A seedling planting device comprises a connection device 3 for coupling an extended slide plate 21B to a main slide plate 21A, in a manner of capable of changing a posture of the extended slide plate between a work posture at which the extended slide plate is along an extension direction of the main slide plate 21A, and a storage posture at which the extended slide plate is positioned out of the extension direction of the main slide plate 21A, in which the connection device 3 comprises a plurality of oscillation shaft centers which are a first oscillation shaft center p1 capable of oscillating and operating the extended slide plate 21B in a direction crossing a lateral movement direction of a seedling mount base, and a second oscillation shaft center p2 capable of oscillating and operating the extended slide plate 21B in a direction different from the oscillation/operation direction around the first oscillation shaft center p1.SELECTED DRAWING: Figure 5【課題】最外側部分の摺動板の折り畳みを、比較的簡単に、かつ他部材との干渉を避けながら容易に行える苗植付装置を提供する。【解決手段】主摺動板２１Ａに対して延長摺動板２１Ｂを、主摺動板２１Ａの延長方向に沿わせた作業姿勢と、主摺動板２１Ａの延長方向から外れて位置する格納姿勢と、に姿勢変更可能に連結する接続装置３が備えられ、接続装置３が、苗のせ台の横移動方向に交差する方向へ延長摺動板２１Ｂを揺動操作可能な第一揺動軸心ｐ１と、その第一揺動軸心ｐ１回りでの揺動操作方向とは異なる方向へ延長摺動板２１Ｂを揺動操作可能な第二揺動軸心ｐ２と、の複数の揺動軸心を備えたものである。【選択図】図５
