Financial activity takes the form of obtaining resources/revenue and carrying out public expenditure, requiring financial analysis, investment planning, evaluation of the operation carried out and control of public finances. This control has been a huge challenge for many states, preventing them from achieving their objectives. This work is divided into three chapters. The first chapter analyzes how the rule of law has developed the control of public administrations. The second chapter looks at the mechanisms used to control the state's financial activity. The third chapter focuses on control, supervision and the mechanisms applied in various countries to ensure good management of financial activities and responsibilities.