Ferrogmagnetic resonance excitation and its use for heating substrates that are filled with particles

Method for heating a substrate, relative to the total weight of the substrate, containing 0, 1 to 70% by weight of metal particles, magnetic, ferrimagnetic, ferromagnetic, antiferromagnetic or superparamagnetic with an average particle size comprised between 1 and 5000 mm, subjecting the substrate to electromagnetic radiation, wherein the electromagnetic radiation is microwave radiation with a frequency in the range of 1 to 300 GHz, and because while the substrate is allowed to act one equidirectional magnetic field whose intensity field is at least twice higher than the intensity of the geomagnetic field.