A rice seedling cultivation device comprising an illumination device 13, the rice seedling cultivation device cultivating rice seedlings in multilevel-shelf plant growing devices 3-8, wherein the rice seedling cultivation device is characterized in that the illumination device 13 comprises a semiconductor light source and a resin cover 13b that diffuses light from the semiconductor light source, and the luminous flux of the illumination device 13 output from the illumination device is 17000 lumens or more per 1 m