It takes important part in museum structure and in science activity of museum workers. The Library is basis for scientific, research, collection and popularizing activity of curators, working in different sections.

The Library holds over 16 000 volumes of special science literature. Extremely various are periodic editions and reference books. The Periodic Fund holds editions like “The Balkan Dawn” (1892-1894), “Bulgaria” (1898-1899), “Macedonian Voice” (1894-1895), State Paper – full package of volumes, “Dawn” – printed in Braila (1864), “Peace” – 1894, “The Banner” – 1898, “Freedom” – 1886, and many other. Also in the library are available: Proceedings of Bulgarian Archeological Union, Bulgarian Archeological Institute, Annual editions of Institutes within BAS, proceedings of other Bulgarian museums. Here are kept and collected archaeological, historical, etnological, numismatic editions, and those for Kyustendil region. Among the editions in Fund “District Science” are: “Kyustendil” by G. Drumoharsky, “Mother Ega”, “Fairies and wonders” by P. Lyubenov, editions of Ephrem Karanov, Yordan Ivanov and Yordan Zahariev. In the section “Unique editions” and books with bibliographic value can be found: “Statute of development of Eastern Rumelia” (1879), “Short Bulgarian history” by Dobri Voinikov (1879); “Critical approach in research of Bulgarian history” (1849) by Y. Venelin, etc. There is also a rich collection of materials on Western Ranges and Macedonia. The Library is in relation with district scientists and specialists from these areas.

The Library special services are delivered to students, teachers, academic scientists, scholars, etc. National and foreign exchange is developed.