The aim of this study is to examine Swedish public libraries preservation of rare book collections. In this study a rare book is rare when it become over a hundred years. I will investigate if libraries have any written policies or plans when it comes to preservation and also what the librarians’ opinion about rare book collections are. This is of interest because public libraries have a lack of responsibility when it comes to preservation. The librarians’ opinions will be based on Svante Beckman and Magdalena Hillström’s theory of museums four idealtypes. The four different types are the treasury, the archive, the school and the theatre. The theory then will let us see if the librarians think their rare book collections are subject only for the audience or the collection. I will examine six librarians from six different cities in Sweden. To my help I will use a questionnaire. There will be for example questions about aims, problems, visions and care. The study will then be based on a method of qualitative content analysis. The result of the analysis reveals that the majority of the librarians’ think their rare books are subject for the collections. They includes in the Treasury and the Archive. No preservation documents were written at the chosen libraries and there were only two libraries that had written something about cultural heritage and preservation in their library plans.