Driven by the liberalization of the energy market that began in the 1990s, the European Union aims to unify its internal market and achieve price convergence among all European economies. In light of these objectives, the majority of European countries have successfully established power exchanges, aiming to conduct cross-border transactions in a transparent and reliable manner. This thesis provides a comprehensive overview of the liberalization process of the electricity sector following an analysis in regard of the legal nature of electricity. It is described the adoption of the EU energy packages and the transposition thereof into Greek Law. It is also provided the contribution of the liberalization procedure to the emergence, establishment and operation of power exchanges in Europe, and subsequently in Greece. In the context of the emergence of Hellenic power exchange, it is identified the structure and operation of the electricity markets introduced under the implementation of the EU target model in Greece, which is based upon market coupling for a single European market for electricity. Finally, said thesis refers to special issues are stemming from, inter alia, the increased participation of renewables in the electricity markets in Greece, which should be taken into account for the further deployment of the Greek wholesale electricity market design.