This study was conducted to discuss concrete ways to contribute to the sustainability of the planet by actively applying and using digital and IT resources in libraries. To this end, a survey was conducted for librarians of public libraries, and the results were as follows. First, librarians’ awareness of the seriousness of environmental problems and the degree of eco-friendly activities were very high, but their awareness of library green IT and familiarity with eco-related terms were very low. Nevertheless, there was a high degree of agreement on the importance of applying green IT to libraries. Second, the areas evaluated as having the highest contribution to eco-friendliness and greening of the library were found in the equipment and product operation area, followed by the service area and the network and system area . Third, how do you think library green IT will have a social impact? The highest opinion was given that it could increase the awareness of the library’s social responsibility as a social infrastructure. In conclusion, it seems that the library’s green IT can contribute to improving library perception by making the public perceived as an institution that has a social responsibility as a social infrastructure.