This study was performed in order to analyze the duties of school librarians (teachers) in Region A and developing an indicator to measure the level of activation based on the capabilities of professional personnel in school libraries. To this end, a job analysis table consisting of job areas, duties, and detailed competencies for analyzing the duties of school librarians (teachers) was developed, and a survey was conducted on 695 school librarians (teachers) in Region A based on the table. Based on the survey results, the importance and satisfaction of the job areas, duties, and detailed competencies of school librarians (teachers) were measured, and these were analyzed using methods such as Borich needs analysis and The Locus for Focus model analysis. Finally, based on the job analysis results of school library professionals derived, an indicator for measuring the level of activation based on the capacity of professional personnel in school libraries was developed consisting of five evaluation areas of ‘library management’, ‘information service’, ‘education’, ‘cooperation’, and ‘education activation cases’, 22 evaluation items, and 33 evaluation indicators. In particular, indicators for strengthening the function of supporting teaching and learning activities in school libraries were reinforced, and indicators for responding to the digital transformation were strengthened.