Today most of the European countries included in the Euro area. So, as of 2014, 18 of the 28 European States parties the official currency is the Euro.
The European Union and the "Euro area" differ in the number of participating countries.

The control treatment, the establishment of interest rates and other aspects of monetary policy in the Eurozone is under the jurisdiction of the European Central Bank. The Bank's headquarters is located in Frankfurt am main, and its management involves the largest national banks of Europe. In the European system of Central banks are the main banks of Spain, Italy, Greece, France, Belgium, the Bundesbank and the Luxembourg monetary Institute.

In some countries, the national currency is the Euro

As noted above, in 18 States of the European Union has an official circulation of the Euro. The list of countries participating in the EU with its own currency: Austria, Belgium, Germany, Greece, Ireland, Spain, Italy, Cyprus, Latvia, Luxembourg and Malta, Netherlands, Portugal, Slovakia, Slovenia, Finland, France and Estonia.

Modern national currencies of Europe

The list of European countries-EU member States that have not introduced the Euro as a unit of payment.
Western European countries such as Iceland, Norway and Switzerland are not included in the European Union.
To date, European countries include:

Bulgaria - Bulgarian Lev (BGN). The course is approximately 1:2, i.e. 1 Euro can be exchanged for 2 leva.
United Kingdom - pound sterling (pound, GBP). The exchange rate against the Euro floating. For example, 100 euros can be exchanged for about 83-84 British pounds.
Hungary - Hungarian Forint (HUF). The exchange rate of foreign currencies floating.
Denmark - Danish Krone (DKK). The Euro is tied to the crown in the ratio 7,46038:1.
Lithuania - (planned from 2015 EUR) to Lithuanian lita (LTL). The rate of the lita to the Euro is 3,4528:1.
Poland - Polish zloty (PLN). Exchange rate to Euro in the ratio is 4,193:1.
Romania - Romanian LEU (RON). The ratio of LEU to Euro 4,497:1.
Croatia - Croatian Kuna (HRK). The ratio of Kuna to Euro 7,663:1.
Czech Republic is the Czech crown (CZK). The ratio of crown to Euro 27,45:1.
Sweden - Swedish Krona (SEK). Exchange rate currency to Euro 8,841:1.