Abstract: The invention provides an oxidation method which utilizes a processing tube, a combustion chamber connected to the processing tube, inner and outer coaxial guide tubes connected to the combustion chamber, and an auxiliary combustion chamber connected to the combustion chamber, which includes the steps of placing a plurality of objects at predetermined intervals in the processing tube; generating steam in the combustion chamber by combustion of a mixture of oxygen and hydrogen gases and supplying the steam to the processing tube wherein the steam is generated by individually introducing oxygen gas and hydrogen gas into the combustion chamber through the outer and inner coaxial guide tubes and by heating the hydrogen gas in the inner guide tube or both the inner guide tube and the auxiliary combustion chamber such that ignition of the oxygen and hydrogen gases occurs when the gases come into contact with each other; and preventing a flame generated by the ignition of the gases from reaching an interior surface