The European Union is both a single political and economic community of countries located on the territory of the European continent that have applied for membership in it and which, based on meeting all criteria and meeting all prerequisites for membership, have become full members of the European Union. The European Union seeks to implement policies whose implementation will be mandatory for each member state of the Union, and these policies are, among other things, monetary and fiscal policy. It is precisely this monetary policy, which is the subject of research and the subject of this final paper, that is pursued by the European Central Bank. Only some of the tasks performed by the European Central Bank are to conduct the overall monetary policy, achieve economic growth and create new jobs, which are preceded by concern for price stability and the management of the common currency of the European Union, ie the euro. Out of a total of 27 EU member states, 19 have adopted the euro as their official currency. In this final paper, the monetary policy is explained in detail. The instruments used by the European Central Bank to achieve the goals are listed. Attention is given to the European Central Bank and the European Economic and Monetary Union, as well as to the stages of the process of its creation. Part of this final paper is dedicated to the euro, its appearance and denominations, the advantages and disadvantages of its introduction and the current topic of recent times, the introduction of the euro in the Republic of Croatia.