The main library of the Leningrad Mining Institute was founded in 1773 together with the institute and is one of the oldest and largest technical libraries not only in Leningrad but in the whole USSR. It possesses a great book treasure, which is particularly rich in valuable journals published over many years up to the present, as well as in other modern periodicals. In the history of the library, two periods can be clearly distinguished: the first from the year of foundation until 1917, the year of the October Revolution; the second from the post-revolutionary period to the present day. In the first period, the library was accessible only to a narrow circle of specialists – professors and, in extreme emergencies, diploma students; students had no access. For them, there existed a small textbook library of a few hundred textbooks, which was open only three times a week for 1.5-2 hours. The library presents a completely different picture in the second period, but only from 1921 onwards. A reading room was opened for students, the textbook library was significantly enlarged and transferred to the main library. The outdated catalogues were replaced by new ones corresponding to modern requirements. The periodicals department was completely reorganised. To give a vivid picture of the growth of the main library, we cite the following data: in 1910, its book stock amounted to 80,000 volumes. On 1 January 1938 - 224,000 volumes. In 1910, the library was visited by 10,000 readers. In 1937 - by 150,017 readers. These figures speak for themselves and require no further explanation.