In 1962 was published the Jürgen Habermas’s classical book, Structural Transformations of the Public Sphere. In celebration of these fifty years, this article presents the most important arguments of this book and discusses the main critiques and reformulations that the concept “public sphere” has undergone in the last decades, including the later Habermas works. Finally, it presents some limits and potentialities in the use of the idea of “public sphere” to think about Brazil.