The purpose of this case study is to investigate and analyse the e-book management at a public library. The library organisation was making agreements with a new e-book aggregator in 2019 and hence it is interesting to examine why the library decided to replace the old agreement. Furthermore, the study investigates what differences the new agreement has made for the e-book collection management and the lending service at the library. The empirical material from interviews and document collection was analysed through thematic qualitative content analysis and then analysed from an institutional theory perspective. The study examines how a certain library organisation, as part of an institute, is dealing with new demands and challenges in the field. The essay describes which laws and directions control and impact the e-book management at the public library-organisation investigated. It also maps out the reason behind the shift of e-book providers. The main reason for that was technical difficulties with the e-books and the app. The study also concludes impacts that the shift has made to e-book management and lending at the public library in this case. The shift to a new e-book supplier has led to satisfactions among the interviewed and the e-book lending at the library has increased significantly. There are now fewer technical issues reported to the library concerning the e-books and the number of app users has increased.