Following the requirements of the European Union, Greece has changed its electricity market over the last fifteen years from a state monopoly to a more liberalized and competitive market. This thesis examines the design, legal environment and early impacts of the development of the Target Model and the establishment of the Hellenic Energy Exchange in November 2020. Based on secondary data, including Greek laws, EU regulations, market analysis and academic research, the study uses a qualitative, policy-oriented methodology to critically evaluate institutional and operational changes in the Greek electricity market.