Human dignity and the legitimate freedoms of members of the society are among the fundamental rights of nations, which the government, as the supreme governing body, is responsible for observing. It is important to refer to the history of civilized societies and religious scriptures to confirm that legitimate freedoms have been considered by rulers and demanded by citizens for many years. The current form of power structure in most societies, which takes place in accordance with the separation of powers, requires considering a large governing body to implement and facilitate the observance of these freedoms for individuals. On the other hand, in case of violation of legitimate freedoms and non-observance of these liberating principles mentioned in the constitution, the need for another institution to guarantee these freedoms is felt, and the judiciary is responsible for guaranteeing these freedoms according to the second paragraph of article 156 of the constitution. . In the process of criminal proceedings, compliance with some penal principles will guarantee the legitimate freedom of citizens during the proceedings and proceedings of the courts. In this research, we will deal with the functioning of the judiciary in safeguarding the basic rights of people in the society with a descriptive and analytical study and by checking these principles such as the principle of acquittal, the principle of retroactiveness of criminal laws, the prohibition of torture and the acquisition of illegitimate reasons, and the principles governing the determination of crimes and punishments.