The transfer of legislative power is not only a well-known phenomenon in the EU Member States; it is also often, an employed instrument on the European level, especially in certain areas of Community policy, which require numerous regulations, often passed quickly to cope with changing market circumstances. Since the 1960's, the Council, through a "parent" regulation, has authorized the Commission to enact more specific regulations within a particular policy area. This type of power transfer was governed by Article 202 EC. However, the Commission did not possess carte blanche power to legislate in this manner. The Council made the adoption of implementing acts subject to institutional constraints, in the form of committees through which the interests of member states could be represented. This system came to be known as Comitology. The Lisbon Treaty now introduces two different kinds of power transfer: Article 290 TFEU provides for the possibility to delegate legislative power to the Commission, whereas Article 291 TFEU deals with the implementation of executive and respectively administrative acts. The system of delegated acts does not foresee any Comitology committees - they have been abolished and replaced by the legislators' extended powers of veto and revocation. The continuance of Comitology is solely envisaged in Article 291 TFEU. Therefore, the post Lisbon world now requires distinguishing between delegated and implementing acts, since very different control mechanisms apply to each type of act. This study analyses the purpose and the background of delegating and implementing acts. It further examines the possibilities of legal protection in the EU against new types of delegated and implementing acts. Theresa Ilgner beschäftigt sich mit der Rechtsetzungstätigkeit der Kommission zur Durchführung der Rechtsakte des europäischen Gesetzgebers. Bereits seit den 60er Jahren ermächtigt der Rat die Kommission zum Erlass von Durchführungsrechtsakten unter Beteiligung von sog. Komitologieausschüssen. Mit dem Inkrafttreten des Vertrags von Lissabon ist der rechtliche Rahmen für die Durchführungsrechtsetzung der Kommission jedoch grundlegend geändert worden. Die Autorin untersucht diese institutionellen Veränderungen und nimmt insbesondere deren Auswirkungen auf die Unionsbürger in den Blick. Sie kommt zu dem Schluss, dass die gewaltenteilige Rechtsetzung, das Prinzip der Demokratie sowie die Rechtsstaatlichkeit gestärkt wurden.