The present invention provides a wet-type electrostatic precipitator that can prevent the corrosion of a discharge electrode even if a gas to be treated containing a corrosive mist is treated. In a wet-type electrostatic precipitator having a discharge electrode 14 arranged along a flow path of the gas to be treated 10, a spray nozzle 28 that can spray a water to the upstream side of the discharge electrode 14 is mounted, wherein a wet film is formed on the surface of the discharge electrode 14 with the water sprayed from the spray nozzle 28. The sprayed water is desirably a water vapor or a water droplet having a particle diameter of less than 10 .mu.m.
