There is disclosed an air cleaning apparatus usable regardless of seasons, weather, environmental conditions and the like. The air cleaning apparatus brings air to be treated into contact with a cleaning solution including active oxygen species to purify the air to be treated includes a water tank which stores the cleaning solution, and a temperature controller which controls a temperature of the cleaning solution stored in the water tank. The temperature controller includes a heat exchanger as a cooling/heating unit which cools or heats the cleaning solution stored in the water tank, and controls the temperature of the cleaning solution into 0° C. or more to 40° C. or less.