In the first half of the article the author outlines main characteristics of provincial estates in Inner-Austrian lands (with an emphasis on Carniola), particulary their beginnings, structure, and responsibilities over the halfmillenium history of this institution. In the second part, he first focuses on the importance of diets' archive in general, its origins, and consequently the issue of the original Carniolan Estates' House at Novi Trg, as well as different misfortunes which influenced the destiny of the oldest documents of the estates. Based on the series of registrature protocols, the author tries to reconstruct the system of its original arrangement. He establishes that the protocols were begun to be managed in 1591 (and not in 1509), and the documents were kept in chronological lists inside thematic groups, which had been formed from 1591 to 1645. All documents in protocols are not registred. Furthermore, the author presents the operation of the provincial registry office, particularly after the interventions (cataloguing) of Karl Seifrid Perizhoff. With this first registration of estates fond (material to the year 1782) dealt in greater detail also F. X. Richter and J. Wallner in the 19th century; the later founded the arrangement which exists until nowadays. The material of registration II.-IV. (1783- 1861) was catalogued according to the registration plan, and has preserved its original arrangement. Despite its undoubtfully interesting material, the later is not often used. The first registration, however, is very well visited.