Upon the enforcement of the Regulation (EU) 2017/1939 of 12 October 2017 implementing enhanced cooperation on the establishment of the European Public Prosecutor’s Office ("EPPO") and the commencement of the EPPO's operations in member states as a novelty in European criminal law concerning enhanced cooperation and the protection of European Union's financial interests. This study involves an examination of the complex structure of the European Public Prosecutor's Office, its competencies, and assessing the legal and operational powers of the EPPO in criminal proceedings. The focus lies on reviewing the substantive and formal jurisdiction, as well as the powers of the EPPO in criminal proceedings. Furthermore, it analyses and describes the position of parties in the phases of criminal prosecution and has a look at their procedural rights. It also explains the position of the EPPO in the Republic of Croatia and the implementation process of integrating European Union legislation into Croatia's national legal framework. Additionally, the reflection on the past performance results during the last years of the European Public Prosecutor's Office's operation in the Republic of Croatia.