The European Union (EU) was officially established when the Maastricht Treaty came into power on 1 November 1993, and in 1995 Austria, Sweden and Finland joined the lately established EU. The European Union is a politico-economic union of 28 member states that are located mainly in Europe. The EU operates through a structure of supranational institutions and intergovernmental negotiated decisions by the member states. The institutions are: the European Commission, the Court of Justice of the European Union, the European Council the European Central Bank and the European Parliament. The European Parliament is chosen each five years by EU people.