Generally a liquid or gas fuel used in a boiler is composed of a set of molecules. Each molecule includes a number of atoms, which is composed of a nucleus and electrons orbiting around their nucleus. The molecules have magnetic moments in themselves, and the rotating electrons cause magnetic phenomena. Thus, positive (+) and negative (-) electric charges exists in the fuel’s molecules. For this reason, the fuel particles of the negative and positive electric charges are not split into more minute particles. Accordingly, the fuels are not actively interlocked with oxygen during combustion, thereby causing incomplete combustion. To improve the above, the fuels have been required to be decomposed and ionized. The ionization of the fuel particles is accomplished by the supply of magnetic force from a magnet.