Its statutes define its mission as the conservation, restoration and improvement of the Casa de Mateus, the study, cataloguing and dissemination of its archives and the promotion of cultural, scientific and educational activities consistent with its heritage. In 1971, it was granted the status of a Public Utility Institution by order of the Ministry of Education. In 1973, D. Fernando de Sousa Botelho Albuquerque succeeded the founder as Director-Delegate. Since his death in January 2022, the position has been held by Teresa Margarida Gomez de Sousa Botelho de Albuquerque.