Dhe beginnings of the Stormarner archive system date back to 1924. Initially, local historians looked after the archives; in 1981, a regulated storage of administrative documents began. Since 2002, the archive has been managed by specialised archivists. Around one thousand linear metres of documents are stored here, of which a good 86 percent are from the district administration, mainly from the period from 1950 onwards due to war losses.
The archive material is supplemented by documents from companies that the district helped to found, documents from associations, clubs, foundations, political parties, trade unions and commercial enterprises as well as the estates of people from the worlds of politics and art.
There is also a reference library, which is a member of the Joint Library Network and provides the largest specialised collection of literature from and about Stormarn for research purposes. As a district between the Hanseatic cities of Hamburg and Lübeck, there is a broad-based press landscape. The issues of several daily newspapers are collected in the archive and are mostly available digitally.
A special feature of the Stormarn district archive is the photographic legacy of several journalists, which means that around 400,000 photographs are available as visual contemporary documents, as well as 20,000 slides, more than 5,000 posters, several thousand maps and plans, audio and film material and around 200 interviews with contemporary witnesses. More and more Stormarner archive material can also be found on the Archive Portal-D and in the German Digital Library. Since 2019, the online project "Sharing knowledge" has given interested parties the opportunity to contribute information on previously unknown places and people in photos.