Article 19 establishes the administrative authority of the Chairman of the Tax Authority. The Chairman is responsible for implementing the Tax Law, exercising the Authority's competences, and supervising all staff. To ensure operational efficiency, the Chairman may delegate specific powers to a deputy or director generals. Such delegations are valid for one year and renew automatically unless abolished. This provision ensures the continuous administration of tax matters and provides a legal basis for senior officials to act on behalf of the Chairman in regulatory and enforcement capacities.