PROBLEM TO BE SOLVED: To provide an air filter unit capable of suppressing the generation of ozone as much as possible and improving the deodorizing performance of a filter. SOLUTION: The ion discharging unit 11 for discharging ions from the upstream side without causing corona discharge and an air filter 12 in which a sheet-shaped filter medium is pleated are formed, and one or a plurality of discharge electrodes of the ion discharging unit 11 are provided. As an electrode, an insulator or a semiconductor is provided around the electrode so as not to generate corona discharge, the discharge current per electrode is 1 μA or less, and the air filter 12 has a charged fiber layer 13 that collects particles from the upstream side. , The structure is such that the base material layer 14 supporting the filter shape and the three layers of the conductive fiber layer 15 are bonded together. The base material layer 14 is an amine-based compound, and the ion discharging part 11 and the conductive fiber layer 15 are charged parts. The conductive fiber layer 15 uses activated carbon fiber as a material, the thickness of the activated carbon fiber is equal to or larger than the combined thickness of the charged fiber layer and the base material layer 14, and the most downstream surface of the activated carbon fiber is grounded. Connected to. [Selection diagram] Fig. 2【課題】オゾンの発生を極力抑え、フィルタの脱臭性能を向上することができるエアフィルタユニットを提供する。【解決手段】上流側からコロナ放電をさせずにイオンを放出するイオン放出部11と、シート状濾材をプリーツ化したエアフィルタ12で構成され、イオン放出部11の放電電極を1もしくは複数個の電極とし、電極の周囲にコロナ放電を生じさせないよう絶縁体または半導体を設け、電極1個当たりの放電電流が1μA以下であり、エアフィルタ12は上流側から粒子を捕集する帯電繊維層13と、フィルタ形状を支持する基材層14と、導電繊維層15の3層が貼り合わさった構造であり、基材層14はアミン系化合物であり、イオン放出部11と導電繊維層15で荷電部を形成し、導電繊維層15は素材として活性炭素繊維を用い、前記活性炭素繊維の厚みが前記帯電繊維層と基材層14を合わせた厚み以上であり、活性炭素繊維の最下流面をアースに接続した。【選択図】図2