To provide an air cleaner by which the environment in the inside of a coating booth is improved.

A water filter is used in combination with a fibrous filter 2 for a clean room. Many spray nozzles 5 are arranged in the upper part of the obliquely arranged fibrous filter 2. Spray water atomized in an umbrella shape is made vortical by high-speed air flow sucked into the fibrous filter 2 and is uniformly diffused. A regulation cover 3 is freely closably arranged in the rear part of the obliquely arranged fibrous filter 2. An air-cleaning chamber 1 holding the above filter or the like is joined to a coating booth through a fan. Thereby, not only fine particles in air but also volatile harmful substance are completely removed by adsorption of the water filter and the fibrous filter. Working environment and coating quality in the inside of the coating booth are improved.