To eliminate hazardous substances causing air pollution by completely burning combustion explosion state in an engine, create a pollution-free engine, save fuel consumption, maximize mileage per litter, lighten an overload to the engine caused by combustion explosion, and realize stable engine operation.

Fuel to be supplied to the engine is previously heated, vaporized or injected, and suction air is also previously heated, and they are sucked. A mixture is completely burned independent of the atmospheric temperature surrounding the engine.