A protection device for land vehicles against mines, wherein it incorporates a metallic plate positioned under the vehicle so as to normalize the magnetic field generated by the vehicle and/or by its elements and at least one loop positioned under the metallic plate and made of an electrically conductive material connected to an electrical supply so as to generate a magnetic field of a value substantially equal to the opposing sign of the magnetic field from the vehicle so as to render said vehicle undetectable by magnetic detection mines.