Abstract: Disclosed is a wet air purifier that eliminates contaminants while contaminated air passes therethrough by causing the contaminated air to come into contact with water. The wet air purifier suctions external air by rotating a rotary fan installed therein and disperses water droplets by causing water to collide with a rotary fan to increase a contact surface between air and water. In the wet air purifier, a mixture of the contaminated external air and the water is made to pass through a long narrow passage and guided to a storage tank in which contaminants are settled. In this way, the wet air purifier increases a retention time and a collision time of water and contaminated air. The wet air purifier also can function as a humidifier.