The Library of Fondazione Eni Enrico Mattei has a collection of about 5.400 volumes.

Library users are requested to follow the Library Rules:

Access is permitted solely for consultation of Library's holdings. To be admitted to the library, a numbered badge must be shown at the Library Office on the second floor of the Foundation's premises. The badge is provided by the reception at the ground floor upon presentation of an identity card. Bags and briefcases must be left in custody at the reception. Smoke, food, drinks and use of cellular telephones are strictly forbidden. Fondazione Mattei does not take on any responsibility for thefts and loss of personal belongings.

Users have open access to the stacks; after consulting, the materials must be placed on the trolley in the reading room for reshelving by the library staff. Consultation outside of the Library is not allowed. External loans are not provided.

Photoduplication is admitted in accordance with Italian law no. 633 of April 22, 1941; the user is responsible for the use of the photocopied material.