PROBLEM TO BE SOLVED: To provide a plant-cultivating device in a ship, having swing resistance against the swing of the ship, hardly causing leakage of a water culture medium (nutritious liquid) fed to a culture bed even if the ship is swung, and enabling a required amount of plants to be cultivated and successively harvested in a short time in a small space; and to provide a method for using the device. SOLUTION: The plant-cultivating device has the culture bed 21, a culture panel 22 having many small holes 28 for carrying carriers 23 in which the plants are set, the carriers 23 arranged in the many small holes 28 so as to plug the holes 28, and comprising an open-cell foamed resin material, an artificial light source 31, and a nutritious liquid-feeding means for circulating the nutritious liquid between the culture bed 21 and a nutritious liquid tank 29. The culture panel 22 has concave parts 32 for absorbing the overflow of the nutritious liquid, and arranged at the surroundings of the small holes 28. COPYRIGHT: (C)2004,JPO&NCIPI