PROBLEM TO BE SOLVED: To provide a technique for preventing deterioration of leaves by bringing a grown plant into a float plate.SOLUTION: A float plate set 10 for supporting a pot for water culture comprises: a float plate 1A which has a plurality of insertion holes 2A in which a pot is inserted and a float plate 1B which has a plurality of insertion holes 2B in which the pot is inserted, the insertion holes 2B being arranged at a pitch larger than a pitch of the insertion holes 2A. The height of the pot, based on the upper surface of the float plate 1B, when the pot is inserted in the insertion hole 2B is higher than the height of the pot, based on the upper surface of the float plate 1A, when the pot is inserted in the insertion hole 2A.