Il legittimo affidamento nel diritto amministrativo, tra principio e situazione giuridica soggettiva.

The thesis concerns the legitimate expectations of a private citizen in respect to the action of the public administration. The legal protection of the legitimate expectations of a private citizens in the administrative law has not been always recognized. So that, the first chapter of the thesis, analyze the beginning of the opinions wich, for the first time, begins to propose the protection of the expectations, in certain conditions, that a private citizen may have arise in respect to a administrative act. So in this part of the work, are analyzed doctrine and jurisprudence, both at national and EU level, especially the decisions of the Italian Constitutional Court and of the European Cpurt of Justice. The second part of the thesis is about the italian legislation – and his interpretation by the jurysprudence and the doctrine – on the possibility of a protection of the expectation of a private citizen, when the public administration issues an act which accept a private application, but, later, annull the act. So, in particular, the chapter analyzes if and when it is possible, for the private citizen, to obtain by the judge the annullment of the administrative second act, in accordance to the protection of the expectation of the private citizens, who, in good faith, have considered the first act as a final one. In the third and last chapter, it is analyzed the legal protection of the expectations when it is not possible to obtain the annulment of the administrative second act and, in particular, the possibile compensation that the private may obtain by the judge in this situation. So that, the chapter analyzes especially if the private have a full right of compensation (“diritto soggettivo”), or it is a different situation, the one that In Italy is called “interesse legittimo”, which is also relevant to determine if the judges which is competent to decides the cases is the civil judge or the administrative judge.