A gas-liquid contactor is obtained by including a header pipe for supplying washing water, in a direction perpendicular to a vertical axis direction, the header pipe being disposed above a packed bed contacting section through which exhaust gas moves upward and passes; and spray nozzles for discharging spray water, the nozzles being disposed, in an upward orientation, with predetermined intervals on the header pipe. The spray water that has been discharged from the spray nozzles is supplied at a low liquid flow rate. The discharged spray water becomes a liquid film and falls downward along the surface of the header pipe, and then falls and spreads in the packed bed contacting section, so that the washing water is made to contact the exhaust gas moving upward through the packed bed contacting section. Accordingly, the washing water is used to clear and remove water-soluble substances contained in the exhaust gas.