Gigantic accumulators of electromagnetic energy will someday be created in outer space. One of the variants of such a storage device is a magnetoelectric flat capacitor, in which dissimilar electric charges located on the plates create an electric field of strength E, and the circular current of the superconducting substrate (isolated from the plates) creates a magnetic field of induction B, equal in magnitude (in the CGS system) E. In such a capacitor, the magnetic field that pushes the plates apart will be equal to the electric pressure that attracts the plates, and in general the capacitor will be in equilibrium. Therefore, it is possible to create such drives of very large sizes, since they do not require additional fasteners. Prove that the equilibrium in the accumulator does not change when they move both along and across the plates.