PURPOSE: To facilitate seedling transfer, protect the roots of the seedlings from sunlight and prevent the seedlings from falling, by providing pillow members for softly pressing the seedlings on a hydroponic bed.

CONSTITUTION: In planting seedlings 4 on a hydroponic bed 1, said seedlings are protected with pillow members 3 so as not to fall. When the seedlings 4 are to be transferred on the bed 1, said pillow members 3 have only to be moved. Also, shielding of sunlight by the pillow members 3 enables the root area to be retained under favorable conditions. Furthermore, said pillow members 3 can be placed at any positions, so the distances between the seedlings 4 can be set arbitrarily.