In this study, libraries of national and public universities, libraries of private universities, libraries of colleges, public libraries of local governments were selected to measure, compare and analyze the differences in job satisfaction of librarians working in different types of libraries. As for measurement items, 10 factors for job satisfaction were chosen. In doing so, this researcher compared and analyzed the overall job satisfaction and work satisfaction, employment satisfaction, satisfaction with promotion system, satisfaction with work distribution, satisfaction with payment system, satisfaction with service system, satisfaction with facility environment, satisfaction with educational training, satisfaction with welfare system, and satisfaction with personal relations. The results of the analysis on job satisfaction with each factor by librarians working in different types of libraries are presented as follows. First, the overall job satisfaction value of the librarians was 3.940, which means relatively high satisfaction, and in terms of a type of library, libraries of private universities showed the highest value, and the next ones were found to be libraries of colleges, public libraries and libraries of national and public libraries. Secondly, regarding the ranking of the overall satisfaction with the selected 10 job satisfaction factors by different types of libraries, educational training was found to rank the highest, and the next ones were surveyed to be the job, the service system, the personal relations, the employment system, the work distribution, the facility environment, the payment system, the welfare system, and the promotion system.