PROBLEM TO BE SOLVED: To improve a light condition of a plant growing on a cultivation bed of each stage in cultivating plants on a multistage by using lighting devices.SOLUTION: In the present invention, light reflection members 40 are provided on side areas of a cultivation bed 50. Therefore, light of a lighting device 60 above the cultivation bed 50 reflects on the light reflection members 40, and easily hits onto side leaves A which are positioned below a plant growing on the cultivation bed 40. According to the present invention, without directly stimulating growing points, light stimulation can be given to the side leaves positioned in lower areas, so that photosynthesis becomes active, and growth of the growing points can be promoted as a result.
