This book examines the realities of the functioning of the European Public Prosecutor’s Office (EPPO) along with the actual cooperation with other stakeholders in the EU and in the Member States. The protection of financial interests of the European Union is a Treaty obligation bearing equally on the Member States and the Union itself. In order to increase the effectiveness of the investigations and prosecutions in those areas falling under the PIF Directive, using enhanced cooperation provisions, 22 Member States established the office of The European Public Prosecutor which came into operation in 2021. Based on examples of five Member States taking part in the EPPO from the beginning - Germany, Italy, Lithuania, Romania and Slovakia - as well as Poland, which used to be a non-participating Member State and only recently joined the EPPO, this collection analyses the legal framework as well as the practical experience of cooperation in this field. The book will be an invaluable resource for academics and researchers in the areas of EU Criminal Law, EU Law and EU Constitutional Law.