This essay presents the framework for new comparative research in the field of administrative law, with a focus on the European legal area. It is divided into two parts. In Part I, we argue that some difficulties that beset the traditional uses of the comparative method are even more evident when considering the field of administrative law. Accordingly, a methodological shift is needed in more than one sense. First, instead of focusing on either similarities or differences between national legal systems, both analogies and differences must be considered. Second, legal comparison, properly intended, differs from a mere juxtaposition of national administrative laws. Third, the over-emphasis on legislation is even less justified in the field of administrative law, which calls for careful attention to judicial and institutional practices. In this perspective, we briefly illustrate the methodology grounded in a factual approach that has been developed in the field of comparative private law in the last few decades and the way we are going to apply it into our research on administrative law, viewed through a procedural lens. In Part II we discuss the main pillars that characterize our research concerning administrative law: first, its goal, which is the advancement of knowledge; second, the choice to focus on administrative procedure, instead of judicial review of administrative action; third, the methodology, which combines a synchronic comparison, concerning modern legal systems, with a diachronic comparison, that is to say a retrospective on some aspects of the history of legal institutions that look particularly relevant; and fourth, the choice of the legal systems selected for comparison, including a variety of states and a non-state, the European Union.