The present invention allows the contaminated air sucked for the combustion oxidation treatment to be uniformly spread over the entire area of the filter and prevents the durability imbalance deterioration of the filter, thereby extending the life of the filter and increasing the collection rate. It relates to a high-efficiency plasma deodorizer using a non-powered fan, and more specifically, the air diffusion unit diffuses the contaminated air supplied to the pre-treatment filter unit side so that it can be spread evenly over the entire area of the pre-treatment filter unit, resulting in unbalanced durability By preventing degradation, it is possible to expect the effects of extending the life of the pre-treatment filter unit, increasing utilization, and increasing the collection rate, and also, pre-processing is performed by uniformly distributing the intake contaminated air to the pre-treatment filter unit. In the treatment process, the efficiency of combustion oxidation and deodorization of polluted air is maximized. Providing an effect that can be made, and the rear diffusion member distributes the polluted air while revolving around a plurality of main rotational shafts, and each has an additional rotational structure, thereby effectively diffusing the contaminated air in all directions. Provides A high-efficiency plasma deodorizer using a non-powered fan according to the present invention has a housing for which an inner space is formed and an inlet through which contaminated air enters the inner space and an outlet through which purified air is discharged, respectively； A pre-treatment filter unit built into the housing to purify contaminated air flowing into the housing； A plasma generator which is built in the housing and generates plasma in the air that has passed through the pretreatment filter unit to ionize contaminated air； A post-processing filter unit embedded in the housing and purifying ionized air generated through the plasma generating unit； And
