PROBLEM TO BE SOLVED: To provide a seedling transplanter, having good working efficiency and fuel economy by automatically stopping an engine when an operator leaves a maneuvering seat and actuating the engine when the operator returns to the maneuvering seat in performing seedling supplement work.SOLUTION: A rear part of a traveling vehicle body 7 traveled by the driving force of an engine 18 is provided with a seedling planting part 15 for planting a seedling in a field, a maneuvering seat 3 is provided on the traveling vehicle body 7, the maneuvering seat 3 is provided with a seating detection member 16 for detecting boarding of an operator, the front part of the traveling vehicle body 7 is provided with a preliminary seedling frame 6 loaded with a preliminary seedling, and the preliminary seedling frame 6 is provided with a seedling detection member 17 for detecting loading of the seedling. When the seating detection member 16 is in the non-detection state, and the seedling detection member 17 is in the detecting state, the engine 18 is automatically stopped, and when the seating detection member 16 enters the detecting state during the stop of the engine 18, the engine 18 is automatically started.【課題】苗の補充作業を行う際、作業者が操縦座席から離れると自動的にエンジンが停止し、苗の補充作業後に作業者が操縦座席に戻ると自動的にエンジンが作動する、作業能率や燃費のよい苗移植機を提供する。【解決手段】エンジン１８の駆動力によって走行する走行車体７の後部に圃場に苗を植え付ける苗植付部１５を設け、走行車体７上に操縦座席３を設け、操縦座席３に作業者が搭乗したことを検知する着座検知部材１６を設け、走行車体７の前部に予備の苗を積載する予備苗枠６を設け、予備苗枠６に苗の積載を検知する苗検知部材１７を設け、着座検知部材１６が非検知状態であり、苗検知部材１７が検知状態であるときはエンジン１８を自動停止させ、エンジン１８が停止中に着座検知部材１６が検知状態になると、エンジン１８を自動的に起動させる構成とする。【選択図】図５
