The present article proposes to analyze the aspects related to judicial legitimation in the process of construction of the legal norm in the concrete case, in the paradigm of legal post-positivism. The process of creating the legal norm in belongs, in the system of separation of powers, to the Legislature, composed of members directly elected by the people. The Judiciary, while one of the powers of the Republic, is composed of members not elected by the people, which allows the discussion about the judicial legitimation of the decisions that create the legal norm applicable to the concrete case. In this sense, we present the present scientific article that will investigate the necessary requirements for the validation of the creative activity of the right by the organs of the Judiciary Power in the concrete case, in light of the structuring theory of the norm developed by Friedrich Müller.