Metrology is a scientific and technical branch closely connected to the existence and development of another fields or areas of technical or another application character. These fields include mainly production, transport, telecommunication, health service, business etc. Metrology is used for a quantitative determination and stipulation of different effects, conditions and properties within these disciplines. The course is devoted to the explanation of the theoretical base of metrology, the so-called metrological physics. It includes description of the system of physical quantities and units; and selected physical laws, which form the principles of measurements. Moreover, in the frame of the course different methods of measurements will be discussed, including the techniques for minimising the influence of systematic errors that usually have physical merits.