This work aims to analyze the portfolio in public policies for teacher education. Documentary research of Curriculum Guidelines for Teacher Education in Brazil (the Resolutions of 2015 and 2019). In policies, objectives and roles / functions assigned to the portfolio are identified; which is also analyzed as an education device from the perspective of teacher professionalization. The results show similarities and differences between them. In both Resolutions, the portfolio gains an instrumental support role and a registration function, in the supervised internship. In the 2015 Resolution, the portfolio has the objective of enabling the interns to reflect on the practice; and the functions of systematization, monitoring and research - therefore, bringing it closer to an open and flexible education device, that is consistent with teaching professionalization. However, in the 2019 Resolution, the portfolio appears with the objective of evaluating the intern (learning) and with a compilation function, under a logic impoverished of technical artifact of controlled rational activity (control device), which does not contribute to professionalism in teacher education. The portfolio, as a pedagogical device, deserves attention in teacher education policies; given that it can both boost and tension the construction of the teaching profession.