PROBLEM TO BE SOLVED: To provide a seedling transplanter capable of suppressing erroneous detection of a conveyance motion of a seedling box.SOLUTION: The seedling transplanter includes: a pot seedling mount part mounting a seedling box storing pot seedlings a seedling box conveyance device feeding a seedling box on the pot seedling mount part by pot seedling a seedling taking-out device taking out the pot seedling from the seedling box a seedling planting device planting the pot seedling taken out by the seedling taking-out device on a farm field and a conveyance motion determination device 26. The conveyance motion determination device 26 includes: a conveyance time detection device 47 detecting a feeding action of the seedling box by the seedling box conveyance device a movement detection device 49 detecting movement of the seedling box by the seedling box conveyance device and a notification device 50 performing notification when the movement detection device 49 detects no movement of the seedling box during a time when the conveyance time detection device 47 detects a predetermined number of times of feeding motion of the seedling box.
