Abstract

The contribution deals with the theme of the nullity of an administrative decision, illustrating its doctrinal and legal evolutionfrom form the idea that mathed nullity to non-existence to the codification of the declarative action of nullity by Art. 31 of the Code of Administrative Procedure. With reference to the system in force, the author intends to demonstrate that three different kinds of nullity are identifiable, each characterized by its own ratio and by particular procedural arrangements: nullity due to violation or elusion of res judicata conferred to exclusive jurisdiction of the administrative court, textual nullity conferred to the administrative court and ascertainable in the form of the declarative action of nullity pursuant to Art. 31 of the Code of Administrative Procedure, nullity/nonexistence owing to a lack of one of the essential elements and to an absolute defect of attribution, for the ascertainment of which the jurisdiction and the consequent procedural arrangements must be determined based on the nature of the complaint issued by the claimant.