The Library of Fondazione Eni Enrico Mattei has a collection of about 5,000 volumes.

As of 2015 users can access online the complete collection of Science Direct Corporate Edition by Elsevier (about 2500 titles) from the Library computers. All the titles in the list can be accessed from the platform SCIENCE DIRECT and the full texts are downloadable from January 1995 until today.

Library users are requested to follow the Library Rules:

The Library is open:
Monday to Friday, from 9.00 a.m. to 1.00 p.m.

FEEM may deny access to the library or consultation of the material requested.
Personal data and information will be used for internal purposes only, as indicated in the INFORMATIVE NOTE.

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. 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.