According to Greek Law 4757/20 (Government Gazette A/240/1.12.2020), "Establishment, operation and responsibilities of the Civil Aviation Authority (CAA), regulation of issues relating to the Civil Aviation Authority and other provisions under the responsibility of the Ministry of Infrastructure and Transport", the Οperation and the Organizational Structure of the HCAA were established.
 The Department of Aircraft Registry and Airworthiness in under the Directorate of Flight Standards, which is under the Directorate General for Aviation Activities.
It is responsible, among others, for 
(1) regulating and continuously supervising the airworthiness of aircraft 
(2) the certification of organisations for maintenance, continuing airworthiness, design, certification, production of aircraft, parts, components and training 
(3) cooperation with the International Civil Aviation Organisation, the European Commission, the European Aviation Safety Agency (EASA) and any other organisation or authority on matters within their remit.
In other words, the Department of Airworthiness is responsible for the accomplishment of Organizations safety oversight in the field of Initial and Continuing Airworthiness, Aircraft Maintenance, Aircraft Maintenance Training, Aircraft and assossiated components certification and production Organizations.