The main point of the diploma essay is given upon a status of defendant in criminal legislation considering the right of a trial within the reasonable time. The term of equity is presented as a ground of a trial within a reasonable time. Through legal regulation possibility of different effects on duration of the same is explained, as well as the impact of the actions of public authorities, not only the subjects of criminal proceeding. The importance of effective organisation, work division and monitoring the actions of public authorities as an important role in normal criminal proceeding are described as well. In historical part of the diploma essay, the development of this right is analysed through the centuries, as well as the importance of the same in three main models of criminal proceedings. The main point of the essay is given on the role of case law of European Court of Human Rights and its influence on national legislation. Going futher, the possibilities of abuse of procedural rights from the aspect of defendant and the prescribed sanctions for the same are discribed. The case law of ECHR is analysed through the cases against Republic of Croatia, considering the important role which has it in Croatian legislation. Moreover, the case law is presented in such way as to show the main problems of croatian legislation, especially the problem of trial within reasonable time caused by the public authorities and abuse of procedural rights. The responsability for unreasonably too long criminal proceeding is described from the aspect of cooperation and connection of legislative, executive and judicial authorities, the role of state budget, different possibilities for young advocates and encourage citizens on non-judicial dispute of their litigations. At the end of diploma essay, it is given short review of development of effective legal remedy from the ground of the case law of European Court of Human Rights.