PROBLEM TO BE SOLVED: To promote the growth of a cultivated plant by soaking the root part of the cultivated plant in a nutritious liquid while keeping the soaked root part at a proper length, to enable the optimum growing environment of the cultivated plant to be kept, and radiating far infrared rays at the vicinity region of the root part of the cultivated plant to activate and ionize the nutritious liquid. SOLUTION: A bed 1 for hydroponics stores the nutritious liquid 2. A float panel 3 for a raising pot in a state in which the panel 3 holds the raising pot 4 is regulated so as to float on the nutritious liquid 2. Each raising pot 4 is kept in a state in which a part of the raising pot 4 is soaked in the nutritious liquid 2 by the float panel 3 for the raising pot. The raising pot 4 is formed by injection molding of a resin containing a far infrared-radiating body mixed therewith. COPYRIGHT: (C)2003,JPO