The chapter approaches the EU administrative institutions as catalysts of the development of administrative law of the European Union. As a chapter of the Oxford Handbook on Comparative Administrative Law, it explains the main traits of those institutions, how legal scholarship has portrayed them and how it has addressed the core aspects of their legal regimes. Furthermore, it traces the emergence and current state of EU administrative law, characterising the different roles comparative administrative law has had at different stages. It highlights the initial dissonance between the specificities of the EU administrative institutions and the statematrix of general principles that were developed on the basis of functional comparison; the role of legal scholarship in shaping EU administrative law, in its efforts to give effect to an "utopia" (Chiti, 2007) of an integrated administration constitutionally framed by general principles and fundamental rights; the limits of resorting to comparative administrative law in the context of EU integration and, briefly, the crossroads at which EU administrative law currently stands.The dominance of administrative institutions in regional and global governance is a truism in many important areas of social and economic life. Food quality, pharmaceuticals, product safety, environment, technology and communications are only a few examples. In all these areas, regulation relies on specialised knowledge, discourses and legal acts developed within and adopted by international, regional and national administrative institutions, which, thereby, and by force of the powers allocated to them, have become central to modern government. At the same time, the proliferation of administrative institutions beyond the state challenged the role and functions of their national counter-parts. They have emerged largely detached from constitutionally framed or stable procedural and substantive rules that, within a state-setting, had provided safer ground for the protection of rights and the legitimacy of democratic processes (Sand, 1998, 274), and they evolved as those rules were being framed. As they progressively changed the governing conditions within the state, the challenges they have posed to democratic government and to rights' protection soon became those of national administrative institutions too (Sand, 1998, 276). From this perspective, the 'level' image, whereby supranational and transnational administrative institutions operate 'beyond the state' is as deceptive as it is descriptively appealing. This chapter will focus on the administrative institutions of the EU. It is hoped that the Eurocentric-bias of the analysis can nevertheless be useful as a reference point for the study of 1 I would like to acknowledge helpful suggestions by Peter Cane and Filipe Brito Bastos.