In 1987, the Board of Catalana de Gas created the Historical Archive, witness to the activities and technology of the company since 1843. Since 2004, the Gas Natural Fenosa Foundation has assumed its conservation, cataloguing and circulation. Currently, the Archive is housed at the Gas Museum, home of the Gas Natural Fenosa Foundation, in order to expand research and educational and research proposals of the Museum through the written, graphic and oral documents gathered together in it.

The Archive occupies more than 3,000 linear metres of documentation that is distributed among 50 collections. These collections correspond to the main company (Gas Natural Fenosa) and the subsidiaries acquired over the years. Among the documents conserved are photographs, maps, reports, acts, deeds or actions generated by the company during over 160 years of history. The collection of the Historical Archive is listed and described in accordance with the Standard Archival Description of Catalonia (NODAC).

The Archive also has a large library and historical archive with works of reference.