To provide a seedling transplanter which can perform planting to a desired farm field at a desired number of seedling mats.SOLUTION: A seedling transplanter comprises: a downstream-side rotating body arranged in a position in which the rotating body is rotatable in conjunction with the vertical feed of a seedling mat by a vertical feed mechanism of a seedling placing table when placing one piece of the seedling mat at an upper side from a lower end of a placing face of the seedling placing table； and an upstream-side rotating body arranged in a position in which the rotating body is rotatable in conjunction with the vertical feed of the seedling mat when placing one piece of the seedling mat in a position with an interval larger than at least a vertical length of one piece of the seedling mat from the lower end of the seedling placing face, and at an upper side of the downstream-side rotating body. The number of times of the seedling-loading of the seedling mat is detected on the basis of rotation states of the downstream-side rotating body and the upstream-side rotating body, a feed amount of the seedling mat is calculated on the basis of a rotation number of the downstream-side rotating body, and a compression ratio of the seedling mat is calculated on the basis of the calculated feed amount of the seedling mat and the calculated number of times of the seedling-loading of the seedling mat when the upstream-side rotating body is transited to a non-rotation state from a state that the upstream-side rotating body rotates in conjunction with the vertical feed of the seedling mat.SELECTED DRAWING: Figure 12【課題】所望の圃場に対して所望の苗マット数で植付を行うことができる田植機を提供する。【解決手段】苗載台の載置面の下端から上方側に苗マットを一枚置いたときに、苗載台の縦送り機構による苗マットの縦送りに連動して回転可能な位置に設けられる下流側回転体と、載置面の下端から上方側に少なくとも苗マット一枚の上下長さよりも大きい間隔を空けた位置、かつ、下流側回転体の上方側に苗マットを一枚置いたときに、苗マットの縦送りに連動して回転可能な位置に設けられる上流側回転体と、を設け、下流側回転体及び上流側回転体の回転状態に基づいて、苗マットの苗継回数を検出するとともに、下流側回転体の回転数に基づいて苗マットの送り量を算出し、上流側回転体が前記苗マットの縦送りに連動して回転する状態から、回転していない状態に遷移したときに、算出した苗マットの送り量及
