A seedbed supporting member and a panel supporting member (150) are configured such that, in a state where a seedbed held in a first seedbed holding member (110a) and a through hole portion of a first panel (120a) overlap with each other, a seedbed held in a second seedbed holding member (110b) and a through hole portion of a second panel, which correspond to this seedbed and this through hole portion, respectively, overlap with each other. An arrangement spacing in a first direction between the through hole portion of the first panel (120a) and the through hole portion of the second panel (120b) corresponding to each other is equal to an arrangement spacing in the first direction between a first transplantation arm (130a) and a second transplantation arm (130b).
