The main function of the CIS Library is to provide support for the research work undertaken by the entity. Hence, it possesses a complete list of bibliographic titles essentially specialising in topics related to sociology and political science.
Its collection began in 1963 with the creation of the IOP (Instituto de Opinión Pública), a forebearer of today's CIS. It currently comprises over 30,000 monographic works, for which a bibliographic description is available through the Library Catalogue. It also has editions of 720 periodicals, of which 230 are still published and 47 are available for consultation in digital format. To this we should add a further 403 titles available through the JSTOR journal platform. There is likewise a series of databases which may be accessed online or on an electronic medium.
The library is very useful for students, the teaching profession, researchers and for members of the institution itself.