In 1976, the museum's founder, George Anemogiannis, initiated the Kazantzakis Archive, significantly strengthened by a substantial donation from the author's wife, Eleni Samiou-Kazantzaki. Additionally, numerous private individuals played a crucial role in expanding the archive through significant donations. Enriched by these contributions, the archive remains active, dedicated to preserving and promoting its collections. Today, it houses approximately 50,000 objects and documents, organised into ten collections based on form and content.

Notably, George Anemogiannis bequeathed his well-organised personal archive to the museum, constituting one of Greece's and the world's most comprehensive theatrical archives. This theatrical treasure trove encompasses studies of over four hundred performances, artistic drawings, three-dimensional models of sets and costumes, press publications, photographs, correspondence, documents, notebooks, books, and personal belongings.