The monograph is a comprehensive study of the archive of the Operational Headquarters of the Reichsleiter Rosenberg as a source base on his scientific activities in accordance with the Nazi postulates and tasks of the Headquarters, as well as on the history of Nazi studies of Eastern Europe, primarily Belarus, Russia, Ukraine, Baltic countries - constituting the concept of "eastern space." " In the first part, the structure of the Headquarters, its functions and tasks, directions of search, methodological and research work are considered, the basics of document formation are analyzed, the composition and content of the Headquarters documents are characterized. The second part of the monograph presents a number of documents of the operational headquarters for 1941 - early 1945. in the form of a facsimile, accompanied by a translation into Ukrainian.