PROBLEM TO BE SOLVED: To uniform the density of the seedlings after implantation by implanting in a row the seedlings that are on a base part and preventing from a missing plant when seedlings are separated by a transplanter, and to prevent uneven growth by minimizing damage of the upper roots near a root flare when separating seedlings.SOLUTION: In a seedling collection S in the state of a mat in which plant seedlings N consisting of roots and stem-and-leaf part are allowed to spread deep roots in large numbers into a base part 1 consisting of compost and are implanted, a base part 1 is configured to have a lower part 2 smoothly consecutive from its bottom part 1 with a given height, and an upper part 5 having a plurality of row state parts 4 which are consecutively formed in the lower part 2 in parallel with each other through a slot 3 and with a given interval and in which the stem-and-leaf parts of the seedlings N protrude in large numbers along the longitudinal direction. A raising seedling device K for
