To provide an air cleaning device capable of discharging electricity to a catalytic surface evenly and efficiently.

The air cleaning device comprises a casing 1 with a cylindrical air pathway 1a, an ionizing part 2 disposed on the upstream side of air flow in the air pathway 1a for electrifying moisture molecules or dust, etc., with positive or negative charge, and a catalytic body 3 disposed on the downstream side of an air flow of the ionizing part 2 in the air pathway 1a for forming a catalytic layer 3b supporting a catalyst on the surface of an electrode 3a. The voltage with the same polarity as the ionizing part 2 is applied to the catalytic body 3, and at the same time, the pulse voltage P with the reverse polarity to the ionizing part 2 is applied to the catalytic body 3 in an appropriate cycle only for a short period of time. As a result, the large difference in the electric potential is generated between particulates R and the catalytic body 3, and the electric charge having electrified the particulates R is discharged toward the catalytic body 3. Accordingly, electricity can be discharged to the catalytic surface evenly and efficiently without the particulates R adhering to the catalytic body 3.