To provide a water treating module which has satisfactory maintainability and prevents the occurrence of positional deviation of linear electrodes upon assembling.

The water treating module 2 employs such a structure that electrode support plates 23a, 23b and a mist producing member 24 are stacked via insulating spacers 25a to 25d outside flanges 212, 213 formed on upper and lower edge parts of a cylindrical electrode 21. Further, the upper and lower both edge parts of a linear electrode 22 are retained to be arranged along the center axis of a cylinder part 211 of the cylindrical electrode 21 by the electrode support plates 23a, 23b. By applying high-voltage pulse between the cylindrical electrode 21 and the linear electrode 22, a streamer-like discharge space is formed in the cylinder part 211 and mist-like droplets D of water to be treated drop down in the streamer-like discharge space.