EN
The article concentrates on the numerous functions played by the principle of equality in the European Union law. However, they have not been static but have changed in line with the evolution of the European Community (now European Union) legal order. As a result four main functions of equality are distinguished. Firstly, its role as a an instrument of market integration is presented. The principle of equality have been used in thins filed intensively in order to abolish different barrier in the common market. Secondly, it regulates and can influence the activities of the European Union institutions, both legal and administrative. If these measures are incompatible with the principle of equality, they should be eliminated, so it protects individuals against arbitrary actions. Thirdly, it is an important instrument in eliminating differences in treatment of women and men. The Treaty regulations concerning this questions confirm that sex equality is an important element of the European Union law which aims at its realization in practice. Fourthly, equality taken from the fundamental rights perspective is described (both the case-law and provisions of the Charter of Fundamental Rights are presented). Finally, the provisions of the Treaty of Lisbon are taken into account – according to them equality is both the value on which the Union is based and its autonomous objective. In general one should observe that equality has a special position in the European Union law. Its role has been strengthen in line with the evolution of this legal order and is not confined to economic spheres but can also be looked at from the fundamental rights perspective.