A sensor for measuring the surface level of a liquid phase metal includes an air excitation coil and lower and upper air reception coils. Excitation coil is perpendicular to an upper surface of an ingot mold and powered by a current for generating a magnetic field. Magnetic field lines propagate along upper field lines away from the ingot mold and along lower field lines covering the upper surface and the molten metal surface. Lower air coil is parallel to the excitation coil, whereby an induced voltage is generated by the lower field lines, the latter being modified by varying the level of the metal surface. Upper air coil is parallel to the excitation coil, vertically adjacent to the lower air coil, with a shape and characteristics identical to the lower air coils. Upper field lines generate the induced voltage and are substantially free of disturbances generated by the metal surface.