The Maastrich Treaty established the European union in 1992, ie European Community grew into the European Monetary and Economic union, where special importance was given to the formation of a single European market with emphasis on enabling free movement of people, labor, goods and capital. A few years after the Treaty, member states began negotiations on single currency area an agreement was reached on a common currency, the euro. The Creation of monetary union did not go smoothly, but the desire of member states to cooperate and set up an effective system to eliminate currency risk and market protectionism has led to the achievement of set goals. Carrying out activities and achieveing the set goals would not be possibe without bodies and institutions such as the European Monetary Institute and the European Central Bank, which through phases created the European union as we know it today. The convergence criteria are set out in the Maastricht Agreement and represent an obligation for all members of the European and Monetary Union. According to the criteria, member states should work twoards pemanent adjustment to the other members of the union, and their fullfilment and maintenance will lead to long-term macroeconomic stabilization. The most common occurrence in the period from one to two years before, and one to two years after the introduction of the euro is the difference between perceived and actual inflation. Phenomenon occurs in consumers in the form of expectations and perceptions of a sharp rise in prices, which in reality is measured in much lower value than actualy expected.