The Beopmaru, Supreme Court Library of Korea, the national library of the judiciary, is the only one that can help reduce the justice gap and increase access to justice by allowing the general public and legal experts to read and circulate. Accordingly, this study identified user satisfaction with the Beopmaru public service through surveys and interviews and derived ways to improve the service. User satisfaction was in the following order out of 5 points: response of librarian 4.62 points, facility management 4.48 points, and cultural programs such as events and lectures 4.33 points. Satisfaction with collection composition was the lowest at 3.97 points. This appears to be because collection composition is where legal expertise has the greatest impact on satisfaction. As satisfaction with the collection composition was the lowest, collection expansion was the highest at 44%(114 people) as a service that Beopmaru needs to strengthen in the future, and a balanced collection of books according to the user base is needed in the future. Based on this, improvement measures were proposed to include dualizing the Beopmaru reading space and services for the general public and legal experts, strengthening its identity as a legal library, improving the system, and strengthening publicity and response of librarian. If the Beopmaru public service is successfully established through continuous research in the library and information community, it will be possible to improve the service quality of the law library industry as a whole, including law libraries, and increase user satisfaction.