The Archive of the Biblioteca Nacional de España is responsible for the safekeeping of two documentary assets.
- The Biblioteca Nacional de España Archive. This archive conserves documents it has produced and received since it was founded in 1712, as the Biblioteca Real, through to today.
- The Archive of the Junta Facultativa de Archivos, Bibliotecas y Museos. A documentary asset of extraordinary importance for understanding nearly a whole century of the history of Spain's Archives, Libraries and Museums.