The Kästner biographer Dr Johan Zonneveld handed over his research archive to the IJB, which will be made available to Kästner research under the name "Erich Kästner Research Archive by Johan Zonneveld". In 2024, it is planned to set up an Erich Kästner Research Centre in the Erich Kästner Room of the Foundation International Youth Library and to enable targeted use of the archive there.
The Kästner Research Archive includes books (primary and secondary literature by and about Erich Kästner); articles, original newspaper clippings, programme booklets brochures, postcards, posters; copies of texts by Erich Kästner that only appeared in newspapers and magazines; copies of Kästner autographs; photographs; audiovisual media such as Kästner film adaptations, radio play adaptations, radio, television broadcasts and many more.