CELES2 is a wall-hanging air purifier that purifies air around the user. The existing air purifier has an air quality measuring sensor(measuring device) located inside the appliance. However, the CELES2’s air quality sensor is located “outside” and detachable. First, The user can place the air quality sensor in a space that requires air purification. Then, the main device purify the air based on where the sensor is placed. The device also can be placed at the end of the room until the entire room is clean, or placed near a person to ensure that air around the user is cleaned.