The fifth edition of the 'Administrative Code', which is now structured into nine sections, has followed the evolution of legislation in 2010 and 2011. In addition to the usual modifications to the individual statutes included in the 'Code', this edition has also kept up with the numerous changes that have occurred in the structure of the government mechanism, such as mergers, abolitions, or re-establishments of ministries, the establishment of many new General Secretariats, and the constant redistribution of responsibilities among ministerial structures. The new edition has been supplemented with Law 3852/2010 'New Architecture of Local Government and Decentralized Administration - Kallikratis Program', which, with its adoption, reformed regional administration and local self-government in the country. Because this legislative text, which replaced a series of previously valid provisions, concerns both decentralization and primary and secondary local self-government, the above sections have been consolidated in this revised edition of the 'Administrative Code'. Finally, this volume has been enriched with the most recent regulations regarding the new grading system, the new salary scale for Public Administration personnel, the regime of employment reserve, as well as those related to e-governance and transparency in the public sector. Therefore, we believe that it can contribute to a more comprehensive understanding of the institutional framework of Public Administration in our country, which is a prerequisite not only for its more effective functioning but also for better serving the citizen.