In discharge, a short distance between the high-voltage electrode and the low-voltage electrode is desirable in view of electrical energy. In other words, the high-voltage electrode is preferably extended to be disposed at the front edge of the blowout outlet. However, arranging both of the electrodes in this manner makes the creepage distance between the high-voltage electrode and the low-voltage electrode become significantly shorter, which may cause creeping discharge on the dielectric substrate. Hence, the high-voltage electrode is preferably disposed at a location far enough from above the blowout outlet to prevent creeping discharge from occurring, thereby ensuring an appropriate creepage distance. As mentioned above, the high-voltage electrode is ideally desirable to be disposed at the front edge of the blowout outlet so as to shorten the distance between the high-voltage electrode and the low-voltage electrode. Hence, measures need to be taken to reduce the distance between the high-voltage electrode and the low-voltage electrode while maintaining the creepage distance. As shown in Variation Example 1 and Variation Example 2, the measures include a method in which the protrusion is provided on the dielectric substrate between the high-voltage electrode and the blowout outlet, allows the dielectric substrate to have the protrusion separating the high-voltage electrode from the low-voltage electrode. In addition, as shown in Variation Example 3, the measures to ensure the creepage distance include a method in which the unevenness is provided on the dielectric substrate between the high-voltage electrode and the front edge of the blowout outlet to ensure its creepage distance. In addition, as shown in Variation Example 4, the measures to ensure the creepage distance include a method of configuring a structure in which the end of the low-voltage electrode in the vicinity of the blowout outlet is shaved to make the blowout outlet become wider to ensure the creepage distance between the high-voltage electrode and the low-voltage electrode. In addition, as shown in Variation Example 5, the methods include a method in which the insulator is formed at the end of the high-voltage electrode that is closer to the blowout outlet to forcefully protect the occurrence of direct discharge on the surface. These measures to ensure the creepage distance allow the end of the high-voltage electrode that is closer to the blowout outlet to be disposed closer to the blowout outlet, thus achieving highly efficient plasma generation. Therefore, ensuring the creepage distance and the clearance distance between the high-voltage electrode and the low-voltage electrode prevents unnecessary discharge such as short circuits and creeping discharge between the two electrodes.