Radiofrequency method for level measurement of a dielectric liquid in a tank is described. Two sections of coaxial transmission lines are applied in this method. Coaxial line sections are high frequency resonators. Their resonant frequencies of electromagnetic oscillations are determined and are jointly functionally processed. A result of this processing relates to the level of a liquid and is independent on its dielectric permittivity. Each coaxial line section is connected with input of a correspondent electronic unit. Outputs of these electronic units are connected with correspondent inputs of functional transducer. Its output is connected with register. The coaxial line sections are realized as coaxially located inner and two hollow middle and outer cylindrical conductors. One of the sections is formed by inner conductor and inner surface of middle conductor. The other section is formed by outer surface of middle conductor and outer conductor. Sections (one or both of them) have horizontal parts at lower ends. They are filled in by a liquid and are drained when a liquid flows into a tank and is removed from it accordingly.