AEEGSI is an Italian Regulatory Authority established to satisfy independence and impartiality requirements in the energy sector. Over the years, the Regulatory has changed its features in order to ensure competition among energy operators and in order to compare energy markets and competition distortions and to protect Consumer's interests because there exists asymmetric information and thus, Regulatory was placed at a permanent disadvantage by reason of their relation to the economic operators. The partnership between AEEGSI and ANTITRUST has this purpose. So, the first twenty years of AEEGSI activities show the great skill of the Regulatory to adapt itself to the juridical, social and economic changes. For this reason, AEEGSI has become the most important authority in energy sector and it is very likey that it maintains its role in the future because European economic policy will be based on energy dependent.