The purpose of this article is to give the intelligible procedure for undergraduate students to grasp proof of the fact that the magnetic field outside the hollow superconducting sphere (superconducting shell) coincides with the field of a point magnetic dipole both when an uniform external magnetic field is applied as when a ferromagnetic sphere is located at the shell's geometric center. The proof is based on the London's equation transformation to an integral equation for the vector potential of system. The integral equation may be solved completely in case of the solid sphere.