PURPOSE: To obtain a method for generating an environmental maintenance type artificial rainbow friendly to the earth and a device therefor by converting sunshine energy by solar batteries to electric energy to generate electric power and using this electric power as a driving power source for spraying water drops.

CONSTITUTION: An electric motor 4 is driven on one hand by the effect of a sunshine power generation system 3 generated by the incident sunshine on a solar battery panel 1 and the compressed air of a prescribed pressure is previously charged into a water accumulation tank 8 by an air compressor 6. A pressure regulating valve 27 is opened at need to send the water in this water accumulation tank 8 via a pipeline 26 to a spray unit 30 of a water drop generator 29. The water is sprayed as water drops from respective spray nozzles to form a sectorial water drop curtain 49. The sunshine is cast to this water drop curtain 49 to generate the artificial rainbow 50. In actuality, a consideration to keep rainbow observers 52 free from the splashed water drops is needed by previously constituting a pond 51 around a place where a strut 32 is installed as shown in Fig.