The aim of this paper is to briefly describe and analyze the impact of atmospheric pollutants on library materials, as well as the formation of atmospheric pollutants in the air of the atmosphere that surrounds us. The reasons why it is important for us to preserve the library materials from the inevitable deterioration that is impossible to stop, but it is possible to slow down, are explained. The protection of library materials is a big problem of libraries because parts of our history are irretrievably lost to decay. In order to protect library materials, it is necessary to educate the staff who work with the materials, as well as to invest funds to equip libraries with adequate equipment that will prevent atmospheric pollutants from coming into contact with valuable material heritage. Atmospheric pollutants are described, the way in which they are formed and their impact on library materials, as well as ways to stop their penetration into the library premises. This paper describes how the employees of the Public Library "Petar Preradović" in Bjelovar carry out actions to protect materials from atmospheric pollutants.