A paint booth is provided with a booth body and a purifier. The purifier is provided with a water tank, water rope formation mechanism, sludge removal mechanism, exhaust mechanism, barrier member, inclined plate, and windshield plate. Water falling from nozzles of a water case forms water ropes. The inclined plate has a water receiving surface sloping forwardly down from the barrier member toward a water surface of the water tank. A lower end of the windshield plate is in contact with water in the water tank. An airflow reversal section is formed between a lower end of the inclined plate and the water surface. Air directed downward from an airflow inlet is turned upward at the airflow reversal section and directed to an exhaust chamber through air circulation sections.