PURPOSE: To improve combustion efficiency by inducing electromagnetic induction, changing the molecular structure of petroleum group fuel and turning fuel at the time of vaporization into ultrafine particles.

CONSTITUTION: A strong magnet 1, at central sections of which holes slightly larger than the springs of coil shafts 2 are bored while using coil springs 3 made of stainless as shafts, is plated with nickel for rust prevention, and penetrated. Short-sized coil springs 3 having large diameters are held among anisotropic ferrite magnets and the anisotropic ferrite magnets so that the spaces of the anisotropic ferrite magnets and the anisotropic ferrite magnets are halved to the thickness of the anisotropic ferrite magnet, and fasteners 4 made of stainless are mounted at both ends. An electromagnetic induction inducer 10 is inserted into a fuel tank 5 from the fuel filler hole 6 of a fuel injection pipe 7, and attracted on a bottom in the fuel tank 5 by magnetic force by the magnets 1. Accordingly, magnet 1 themselves are rocked together with the rocking of fuel in the fuel tank 5, and electromagnetic induction efficiency is improved, thus enhancing combustion efficiency.