In this paper, we propose to draw attention to the stability criterion of the superconductor current state. We use for this purpose the rough systems mathematical apparatus allowing us to relate the desired criterion with the dielectric permittivity of the matter and to identify the type of all possible phonons trajectories in its superconducting state. The state of superconductivity in the matter can be explained only by the phonons behavior peculiarity. And on the basis of the above-mentioned assumption, the corresponding mathematical model is constructed. Comment: 9 pages, 0 figures