PURPOSE: To always collect light of sunray, introduce into a semiconductor, and transmit by constructing a global network system of a collecting transmission device of sunray over the daytime and nighttime.

CONSTITUTION: A light transmission network is constructed by spreading large capacity photoconductor cables on the globe. A storage means 1 which transmits and stores collected and focused sunray B is arranged. Light collecting means 2 straggled in each area over each region or the daytime and nighttime on the globe are connected by photoconductor cables. Light emitting means 3 in specified areas in the globe are connected to the storage means 1 through photocables. Sunray B collected by the means 2 and focused in the photocable is transmitted to the means 1, and the sunray in the phototransmission network is always kept in a propagating condition, and stored light in the means 1 is branched and taken out by the means 3 if required.