We have constructed an analytical model of the magnetic field over a region of the Martian surface using satellite raw data and S-approximations within the modified structural-parametric approach. The method mentioned above implies considering the environment features as a function included in an integral. We approximated the anomalous field by the sum of simple and double layers distributed over two concentric spheres lying at different depths below the reference surface. We have presented an analytic downward continuation of the magnetic field of Mars at various distances, including the planet's surface.