It contains a vast volume of documents from the 10th century to today divided into different sections such as Volumes, Registers, or Books.

A large part of its explanatory files can be consulted online. On-site consultations of the documents are carried out by appointment through the cathedral's official contact forms.

The information stored in these archives is fundamental for historical, social, and economic studies. They record both the usual governance of the cathedral and its relations with the population, the Diocese, the City Council, the Crown, Rome, etc.