Human dignity constitutes the basic dynamic of human rights. Human rights, on the other hand, primarily refer to linking the structural conditions of state powers to authority and influence with a rights-based approach. This is where the rule of law comes into play. The fact that the rule of law aims to protect human dignity, both in form and in material terms, reveals the importance of the concept. Because in this way, it is obligatory for the legislature to take into account the basic motivation of the rule of law and human dignity, especially in enacting laws, which is the way the legislature establishes law. Only in this way can a quality law be deduced. The Constitutional Court plays an important role in determining the quality of the law. So, how does the Constitutional Court apply the quality of the law, in other words, the legality test, in its rights-based interpretation? With this perspective, our study examines the principle of legality, which is one of the most important criteria of the Constitutional Court's legality review, taking into account the case law of the European Court of Human Rights (ECHR).