From the construction and the put into operation of the new building of the Seminari Conciliar de Barcelona the year 1882, it is a panoramic view of the existing libraries with public and open access to the city of Barcelona during the first third of the twentieth century, and that serves the same time to pose in value the job developed from the Seminari. First of all, there is a brief presentation of the building of the Seminar, centred on the original location of the Planned Library, but then it becomes the original location of the Library and of its reopening process 15 years later, after which the boxes with all the books were to the underground of the building. Finally, it is to get in context the Library with the other libraries of the city, so as to leave a record of its special importance and significance. As it concluded, even from the very same origins, the paper of diffusion of the culture oberta a tothom has always wanted to have the Library, all its private character