In the "Project for the Brera Specola" compiled in 1772, on the advise and suggestions of Father Ruggero Boscovich, to serve as the policy of the observatory, it states that "The Observatory Superintendent will exchange letters with some of the major European observatories, such as those in Greenwich, Paris and Bologna". This policy can be considered the foundation act for the Observatory archives, which has survived largely intact. The records span in years from about 1740 to 1960, and is, currently, the largest archives among the Italian observatories. The amount of records is proportionate to the importance gained by the Brera Specola. During the 1700s, it was one of the most prominent observatories in Europe in the following century, was the place of work for two outstanding scientists, Giovanni Virginio Schiaparelli and Giovanni Celoria.
Since 1837, the archives has undergone several reorganization attempts, but its present arrangement has been devised by Schiaparelli, who was the director from 1862 to 1900. He alternated between observational activities and history of astronomy, and used the documents of the historical archives to deepen his knowledge of the specola of Milano.
The main archival series (Administrative Archives, Scientific Correspondence, Astronomers' Fonds, and the various series on observations) were thus identified by Schiaparelli and were maintained during the last reorganization.
In addition, this arrangement has been used as a model for the archives of the other astronomical observatories, taking into account the diversities of the records.
After Schiaparelli, the maintenance of the archives had been neglected until 1983. Then, it was decided to reorganize and inventory the materials until 1917. This has led to the publication of the first archives inventory.
In the following years, more records have been found in other places, such as the antique book collections and the deposit archives. These recent discoveries were included in the "Specola 2000" project. At Brera, there are, also, the archival records produced by other institutions: Accademia Fisio-Medico-Statistica of Milano, Comitato Astronomico Nazionale, Associazione Italiana di Aerotecnica and Società Astronomica Italiana.