The Library of the Interorthodox Centre of the Church of Greece was founded in 1971 and is located at the eastern wing of the Holy Monastery of the Assumption of the Virgin Mary in Penteli. The library contains approximately fifteen thousand volumes of greek and foreign books, covering all subjects, mainly religion, philosophy, psychology, social sciences, language, art, literature and history. Most of the collection includes books of theological content. Particular emphasis is given to the coverage of greek and international bibliography of interorthodox and interchristian relations, as well as of the ecumenical movement throughout the history of the Church. The library also contains one hundred thirty titles of greek and foreign journals. The purpose of the library is:
- the selection of modern, interorthodox and interchristian bibliography, which refers to all areas of the theological movement during all stages of the history of the Church of Greece for the fullest theological information of the clergy of the Church of Greece and its theologians or other Church and those who do not belong to any of these groups, but are interested in working scientifically in Greece
- the interorthodox and interchristian movement service and promotion
- the strengthening of the new theologians of the Church of Greece and members of the interorthodox relations in their studies.
The library uses ABEKT to automate its catalog, Anglo-American Cataloging Rules (AACR2) for cataloging, and Dewey Decimal Classification (DDC 22nd ed.) to classify the material. For subject indexing, the NLG and LC Subject Headings and the Thesaurus of the Greek National Documentation Centre are used. The catalogue update is continuous and numbers over 8000 records of books and journals.
The Interorthodox Centre Library participates in the National Collective Scientific Journals Catalogue covering the bibliographical needs of the distant users through their nearby libraries, that spot the material of interest. Furthermore, exploiting the special application of ABEKT, ABEKT Z39.50 Server &Web Gate, the library disposes its electronic catalogue through internet for search by distant users at the environment of access to bibliographical information resources “Argo”.