An electrode for plasma generation according to the present invention includes a plurality of collecting portions having a plurality of through holes, the plurality of collecting portions facing a gas flow in a direction where gas to be treated flows and provided spaced apart from each other. The electrode is applied to a plasma reactor of a treatment device to be provided for a device which discharges the smoke including PM, for example, an exhaust gas purifying device for automobile, or a smoke treatment device used in a facility where the smoke is discharged such as a plant.