Air cleaner

An air cleaner comprising:

• an air-liquid contact part, for bringing the air into contact with a water screen that is formed by spraying, through spray nozzles, circulating water that is retained in a water tank and is supplied under pressure, and for removing visible and invisible foreign materials from the air;
• a liquid separating part, for separating, from the air, tiny water droplets that are included in the air that passes through the air-liquid contact part;
• a cylindrical body into which air to be cleaned is guided, and in which the air-liquid contact part and the liquid separating part are arranged in order;
• a chlorine dioxide addition unit, for adding a stabilized chlorine dioxide solution to the water tank for the water that is circulated;
• and
• a chlorine dioxide activation unit, for activating chlorine dioxide added to the circulating water, that is arranged in a circulating water pipe that extends from the water tank for the circulating water to the spray nozzles located in the air-liquid contact part.