Purpose – The purpose of this master thesis is to generate new knowledge and understanding how the concept of public sphere has been used and understood in library and information research of public libraries. 

Design/methodology/approach –Through a systematic literatur review of  research literature of public libraries and public sphere, interpretations of the public sphere concept are mapped. Qualitative content analysis is applied for the analysis. The research questions are: 1. How is the concept of public sphere interpretated in library and information science (LIS) research about the democratic role of the public library and its role beeing a meeting place and an arena for public debate?  2. What significance can the interpretation of the concept public sphere be assumed to have for the understanding of how LIS researchers view and use the concept? 

Findings – Six themes are identified: 1. Habermas original theory of public sphere from 1962. 2. A theoretical framework of public sphere, based on Habermas theory. 3. Other concepts and theories that can be applied on public libraries and public sphere. 4. A diversity of public spheres. 5. The democratic role of the public libraries and public sphere. 6. Conversation, communication, debate and public sphere.