Most of the developments since 1983 in the management of the geological collections of MNCN are described. At this time Dr. Garcia Guinea assumed the responsibility of Acting Curator of Geology in the Department of Geology (MNCN). After several decades of neglect, the museum has undertaken a new stage of reorganization in order to transform itself into a modern research center in accordance with its potential and tradition. The specimens of the museum's geological collections, often dispersed, have been located and recovered and, subsequently, inventoried and computerized. This work has been made possible by consecutive temporary contracts betwenn the Instituto Nacional Empleo - Consejo Superior Investigaciones Cientificas (INEM-CSIC), signed 5 years ago with the intention of compensating for the shortage of personnel in the MNCN. At present, the mineral collection, containing more than 13,000 specimens, is almost completely processed, with a computer file in which all this information is available. The maintenance and scientific use of collections involves the following: a) Documentation, b) Research, c) Management (loans and consultations, acquisitions and disposal of material, custody of specimens, support to the pedagogic sector, support to research and education, plans). The exhibition and exhibition policy are described concisely, as it is important for public understanding of the collections.