PROBLEM TO BE SOLVED: To provide an air filter unit which exhibits a high dust collecting effect and a high deodorizing effect and can be purified with a low pressure loss. SOLUTION: The air filter 17 is composed of an electrode portion from the upstream side, a pleated air filter 17, a counter electrode layer 29 built in the air filter 17, and an auxiliary counter electrode portion 30 arranged in the air filter 17. From the upstream side of the air flow, a charged fiber layer 18 for collecting particles, an adhesive layer 19 for adhering the charged fiber layer 18 and the base material layer 20, and a base material layer 20 for supporting the filter shape are provided. Reference numeral 20 denotes a chemically adsorbed component, the chemically adsorbed component is an amine-based compound, the adhesive layer 19 and the pleated holding portion 25 contain a conductive component, and the adhesive layer 19 forms a counter electrode layer 29 to hold the pleats. The portion 25 forms the auxiliary counter electrode portion 30, and the potential difference between the electrode portion and the auxiliary counter electrode portion 30 is larger than the potential difference between the electrode portion and the counter electrode layer 29. [Selection diagram] Fig. 6【課題】高い集塵効果と高い脱臭効果を発揮し、低圧力損失で浄化可能なエアフィルタユニットを提供する。【解決手段】上流側から電極部と、プリーツ化したエアフィルタ１７と、エアフィルタ１７に内蔵した対向電極層２９とエアフィルタ１７に配置した補助対向電極部３０とからなり、エアフィルタ１７は、気流の上流側から、粒子を捕集する帯電繊維層１８と、帯電繊維層１８と基材層２０を接着する接着層１９と、フィルタ形状を支持する基材層２０とを備え、基材層２０は化学吸着成分を含み、前記化学吸着成分はアミン系化合物であって、接着層１９とプリーツ保持部２５には導電性成分を含み、接着層１９が対向電極層２９を形成し、プリーツ保持部２５が補助対向電極部３０を形成し、前記電極部と補助対向電極部３０との電位差は、前記電極部と対向電極層２９との電位差に比べて大きい構成にした。【選択図】図６
