PROBLEM TO BE SOLVED: To prevent a flange part of a rear end of a first seedling tray from coming into contact with a flange part of a front end of a second seedling tray.SOLUTION: A vertical conveying device 30 conveys a seedling tray 20 from a tray loading platform 21 to a transplanting part 3. The vertical conveying device 30 comprises: right and left driving sprockets 34; right and left driven wheels 35; right and left endless chains 40 wound between the driving sprockets 34 and the driven wheels 35; a plurality of vertical feeding members 45, 45,,, attached to the left and right endless chains 40; a bottom plate 26 for supporting and guiding a bottom part of the seedling tray 20 between the right and left endless chains 40; and side part guide members 50 for guiding both right and left sides of the seedling tray 20. A passage space S is formed so that the vertical feeding members 45 pass between a start end of the bottom plate 26 and a terminal end of the tray loading platform 21. A step part 26c lowered
