An object is to provide a solar ray lighting device which is capable of reducing the blocking and the shadowing of beams of light reflected by heliostats and which is capable of fixing firmly and stably a heavy and large-sized center reflector. In a beam-down type solar ray lighting device, at least three supporting blocks are assembled together to form a pyramidal shape. In addition, an outer circumferential edge of the center reflector is fixed to the supporting posts so that the outer circumferential edge of the center reflector can internally touch the supporting posts.