The purpose of the research – to reconstruct the network of scientific departments of natural and technical area at Emperor Franz I Imperial Royal University in Lviv during the second half of the XIXth – beginning of the XXth centuries; to describe the structural and personnel transformations which took place in scientific departments. The research methodology is based on the principle of historicism, application of general scientific and special scientific methods, in particular, a comparative historical method, a scrupulous analysis of contemporary statistical and information publications of Lviv University. The scientific novelty of the study consists in the fact that for the first time in Ukrainian and foreign historiography there has been generalized the information on the scientific units of natural and technical direction of Lviv University during the Austrian period (in the previous publications on this issue the emphasis is focused on the departments); a clear scheme (in accordance with scientific areas) of their reorganizations has been made, which is reflected in structural changes, name changes, management, etc. The factual material and concluding statements presented in the publication will be important for the study of the history of science in Galicia. The factual material will become a kind of matrix for further studies in this area of historical local studies. The Conclusions. After the revolution of 1848–1849, the Austrian monarchy, which also influenced the activities of Lviv University, began its reform. It also affected the scientific sphere, taking place in the context of the development of science at that time (from the end of the 1850s – under the influence of positivism). From the middle of the XIXth century the university began to develop a network of units known under the term “scientific institutes” (these included structural units of various fields – technical, natural, humanitarian, as well as the Library). Within the natural sphere, these units included offices, collections, museums, laboratories, institutions, institutes, clinics and dispensaries, seminars, etc., as well as the Botanical Garden. In the majority of publications (since the end of the XIXth century) these units have either not been mentioned at all, or researchers identify them with the departments, consider these units as a part of departments. This approach led to the fact that we often see a lack of interest and attention to the official names of these units, which reflect both their specifics and features of reorganization during the second half of the ХІХth – beginning of the ХХth century. Special attention should be paid to seminars, which from the 1850s till the reform of the 1920s should be interpreted not only as a form of educational process, but also as a scientific institute. During the middle of the XIXth – beginning of the XXth century, on the example of the development of physical and natural sciences, we trace changes in the forms of scientific institutes (for example, office – museum – institution / institute) and observe the formation of scientific schools of famous scientists (heads of scientific units) on the basis of their assistant support staff (assistants, demonstrators, scholarship holders). The development of the network of scientific institutes reflects the development of science in general, the tendency to single out narrower areas (Physics, Meteorology, Astronomy, Chemistry, Geology, Biology, Botany, etc.) from previously integrated fields of scientific knowledge (eg, Physics or Natural History). Medicine, which received a new stage of development from the last third of the XIXth century, had its own specifics in terms of structure at Lviv University and it was intensified with the resumption of the medical faculty activity in 1894. Key words: Lviv University, scientific institutes, physical sciences, natural sciences, museum, seminar, the second half of the XIXth – beginning of the XXth century.