PROBLEM TO BE SOLVED: To enable the removal of a low density methane to be continuously and stably performed for a long period of time without a troublesome maintenance without using an expensive catalyst or the like, and at the same time, to reduce energy burdens for the whole apparatus.SOLUTION: An air purification processing apparatus includes: a raw material feeding section 1 which takes the feeding of raw material air becoming a processing object a preliminary heating section 2 which includes a heat-exchanging means inside, and by which the raw material air having been fed from the raw material feeding section 1 is preliminarily heat-processed a reactor 3 by which the air having been fed from the preliminary heating section 2 is high-temperature-oxidation-treated a recirculation flow passage 4 which connects the feeding-out section of the reactor 3 from which the high-temperature-oxidation-treated air is fed out, and the heat-exchanging means one or more cooling sections 5 and 6 which cool the air having been fed out from the heat-exchanging means through the recirculation flow passage 4 and an adsorption-processing section 7 by which remaining impurities in the air having been cooled by the cooling sections 5 and 6 is adsorption-processed. The raw material air is preliminarily heated to 600°C or higher in the preliminary heating section 2, and heated to 800°C or higher under a no-catalyst condition in the reactor 3.
