The single European market shall ensure the free circulation of goods and other production factors. Because of the freedoms of persons, an employee is able to work in other countries of the European Union without a great effort. Employers can take employees from foreign countries of the European Union or send them to other member states. Because of the difference of wages between the single countries of the European Union, it?s tantalizing for employers, to use people from small wage countries in countries where the wage is higher, to have an advantage over their competitors. To prevent such actions, the Lohn- und Sozialdumpingbekämpfungsgesetz introduced amongst others § 7d AVRAG, which stipulates the employers to have work documents in german language in store, which means, they have to translate them. The European High Court decided, that the German rule of § 19 (2) AEntG, on which the Austrian rule bases, is in accordance with European Union law. It also checked rules of other member states that dictated certain languages for work-documents. This diploma thesis exemplifies these decisions and solves the question, if § 7d AVRAG is in conformity with European Union law and the decisions of the European high court.