A paint booth which comprises a spray chamber accommodating an object to be painted and a purifier for removing paint mist contained in air in the spray chamber, the purifier comprising: a water tank disposed in the spray chamber; and a pump which draws up water in the water tank; a water cord formation mechanism configured to form water cords comprising a water case for accommodating the water drawn up by the pump, the water case comprising a bottom wall formed with a plurality of nozzles, a barrier member comprising a vertically extending wall portion; an exhaust chamber separated from the spray chamber by the barrier member; an exhaust mechanism comprising an exhaust fan for discharging the air in the spray chamber to the outside through the exhaust chamber, the exhaust mechanism being configured to produce airflow such that the air containing the paint mist in the spray chamber contacts the water cords; the purifier characterized in that each of the nozzles comprising an inlet, a tubular portion protruding downward from the bottom wall in such a manner that the inside diameter of the tubular portion is reduced downward from the inlet, and a circular outlet opening at the lower end of the tubular portion, the water which drops in straight lines from the outlets forming a plurality of parallel water cords; and it comprises a splashguard member located above a water surface of the water tank and opposite and just below the nozzles and comprising a water receiving surface which declines from an upper end portion in front of the water cords toward a lower end portion near the barrier member; and a sludge removal mechanism comprising a conveyor disposed in the water tank and configured to discharge paint sludge in the water tank to the outside of the water tank. a water tank disposed in the spray chamber; and a pump which draws up water in the water tank; a water cord formation mechanism configured to form water cords comprising a water case for accommodating the water drawn up by the pump, the water case comprising a bottom wall formed with a plurality of nozzles, a barrier member comprising a vertically extending wall portion; an exhaust chamber separated from the spray chamber by the barrier member; an exhaust mechanism comprising an exhaust fan for discharging the air in the spray chamber to the outside through the exhaust chamber, the exhaust mechanism being configured to produce airflow such that the air containing the paint mist in the spray chamber contacts the water cords; the purifier characterized in that each of the nozzles comprising an inlet, a tubular portion protruding downward from the bottom wall in such a manner that the inside diameter of the tubular portion is reduced downward from the inlet, and a circular outlet opening at the lower end of the tubular portion, the water which drops in straight lines from the outlets forming a plurality of parallel water cords; and it comprises a splashguard member located above a water surface of the water tank and opposite and just below the nozzles and comprising a water receiving surface which declines from an upper end portion in front of the water cords toward a lower end portion near the barrier member; and a sludge removal mechanism comprising a conveyor disposed in the water tank and configured to discharge paint sludge in the water tank to the outside of the water tank.