MULTIPLE STAGE TYPE PLANT-GROWING UNIT

PROBLEM TO BE SOLVED: To provide plural multiple stage type plant-growing units each arranged with plural artificial lights at its ceiling surface as an almost closed space, capable of efficiently utilizing the light irradiated into the almost closed space and also making the luminous intensity of the light at each of the stages as uniform. SOLUTION: The plant-growing units provided by arranging plural units 5, 6 each constituted by piling growing boxes 1 forming the almost closed space for performing the plant growth by using plural light sources 2 in multiple stages, and introducing the irradiated light from the adjacent units 5 on 6 are provided and a light-adjusting tool 3 is provided for adjusting the light source 2 for each of the growing boxes 1 and setting each of the light-adjusting ratios with the light-adjusting tool 3 so as to make the luminous intensity at each of the growing boxes to be the same.