PURPOSE: To sufficiently enhance its magnetize fuel oil being carried to a combustion system so as to magnetization efficiency by applying strong and much magnetism thereto efficiently.

CONSTITUTION: Nb-Fe-B system annular permanent magnets 1 are disposed through each pole piece 2 in a repulsion mode and its magnetic field repeats its cycle in which it increases from zero magnetic field to the max. magnetic field while showing a periodical change across N, S and then becomes zero magnetic field in a magnetic circuit and a non-magnetic tube 8 is disposed in a cylinder core inside a cylindrical casing 7 having an oil entrance 5 on one end and an oil exit 6 on the other end by communicating with the oil entrance 5 in a feeding fuel oil reforming device 4 formed by using the magnetic circuit. The annular permanent magnets 1 are mutually bonded in this nonmagnetic tube 8 through each pole piece 2 in a repulsion relationship and the magnetic circuit making the number of cycle in which magnetic field increased from the zero magnetic field to the max. magnetic field and then becomes zero magnetic field, two or more is fit in the tube 8 and then it is filled and fixed in the casing 7.