PROBLEM TO BE SOLVED: To plant seedlings so that the seedlings are planted at an increased planting density while enlarging the interval between the adjacent seedlings to some extent and the spraying operations of a fertilizer, a chemical, or the like, or weeding operations after planting the seedlings are facilitated, make the common use of a seedling transplanter for planting the seedlings at a conventional interrow spacing as much as possible and the seedlings of the same width as that of the seedlings used in the conventional seedling transplanter. SOLUTION: This apparatus for planting seedlings (a) and (b)is composed so as to actuate two seedling planting units 15a and 15b in mutually different loci T1 and T2, reciprocate either one 15a of the seedling planting units 15a and 15b to one side of the left and right sides, reciprocate the other seedling planting unit 15b to the other side of the left and right sides and plant the seedlings (b) in the lateral side of the seedlings (a) planted with the one seedling planting unit 15a with the other seedling planting unit 15b in the apparatus for planting the seedlings (a) and (b) composed so as to alternately plant the seedlings (a) and (b) in a field with the two seedling planting units 15a and 15b installed in a rotating case 17 driven and rotated around the shaft center X1 in the left and right directions.
