PROBLEM TO BE SOLVED: To provide a seedling transplanter which enable a seedling planting device to plant a seedling at an appropriate planting depth even on an uneven field face, thereby allows the planted seedling to grow favorably.SOLUTION: The seedling transplanter includes: a seedling tray 51 arranged at a rear part of a travel vehicle body 2 via a lift link mechanism 3 and placing seedlings thereon a lift hydraulic cylinder 46 lifting/lowering the seedling tray 51 a seedling planting device 52 taking from a seedling planting part 4 and planting a seedling in a field a center float 55 contacting and leveling a field face a first rotation detection member 67 detecting a vertical rotation angle at a front part of the center float 55 an automatic lift mechanism 69 lifting/lowering the seedling tray 51 by actuating the lift hydraulic cylinder 46 in accordance with a detection amount by the first rotation detection member 67 and a control device 100 including a control constitution expanding or contracting the lift hydraulic cylinder 46 such that a difference becomes smaller than a predetermined value when the difference equal to or larger than the predetermined value occurs between the detection amount by the first rotation detection member 67 and that by a second rotation detection member 68 detecting a vertical rotation angle at a rear part of the center float 55.SELECTED DRAWING: Figure 7
