The provisions of the Agreement on the European Economic Area (EEA) determine the relations of the EFTA countries Norway, Iceland and Liechtenstein with the EU and its Member States. On its basis, these three countries participate extensively in the internal market. The EEA is also discussed as a possible model for relations between the EU and the United Kingdom after Brexit. The new commentary, article by article, explores the importance of the legal practice agreement. It incorporates the extensive annexes and protocols to the agreement, which unlocks key secondary EEA law and establishes links with EU law. The current state of EEA law in Norway, Iceland and Liechtenstein is summarized by legislation and case law. The focus of the presentations lies in the commentary of the EEA regulations on the free movement of goods, the movement of persons, services and capital, transport policy and competition law. The tasks and procedures of the two EEA bodies European Surveillance Authority and EFTA Court, which are used for monitoring and dispute resolution, are explained by commenting on the EEA Regulations and the supplementary agreement concluded between Norway, Iceland and Liechtenstein. The work offers- A comprehensive overview of the special situation in Switzerland- Cross-sectional views on the effects of EEA law in Norway, Iceland and Liechtenstein and on the effects of EEA law in the EU- Important references to the international agreements accompanying the EEA- A comprehensive analysis of the changed legal environment, including the Treaty of Lisbon and other European Treaties. In addition, the commentary provides information on the current state of EEA law in the light of the case law of the EFTA Court and the legislation and case law of the three countries Norway, Iceland and Liechtenstein. For ease of use, the otherwise not easily accessible annexes and protocols, where relevant, and the supplementary agreements are printed.