Effective monitoring of the legality of actions, work and acts of public administration bodies is important for the protection of citizens rights.Public administration needs to gain citizens' trust in the legal actions of their institutions. Even the oldest legal systems were faced with issues of control and supervision of the administration's work, and perhaps the ancient past is responsible for solving control in the future. The concept of the ombudsman dates back to ancient and medieval times, when complaints were received in Athens, they studied and determined whether injustice had been done to the population, they gave the necessary certain measures, and initiated punishment procedures. The Ombudsman in Croatia was established by the Constitution in 1990. The Law on the Ombudsman of 2012 defined tasks and tasks in the field of human rights. Along with the Ombudsman, which is the main from of institution for the protection of human rights, in 2003, the Ombudsperson for Children and the Ombudsperson for Gender Equality were established, and in 2008 the Ombudsperson for People with Disabilities. In the first part of the paper, the concept of administration in theory and Croatian legislation is elaborated. The second part of the paper analyzes the concept of ombudsman and ombudsman, and who is the first ombudsman and what are his powers as part of the legal system.