The dielectric barrier plasma generator of the present invention fails to use microwaves, thus eliminating the need to conduct impedance matching or the like for microwave transmission. Hence, no restriction is applied to the shape of the dielectric substrate, high-voltage electrode, and blowout outlet. In addition, failing to use microwaves eliminates the need to take countermeasures against the leakage of electromagnetic waves. Meanwhile, microwave-induced plasma is generated at a belly of the standing waves where the electric field strength is strong with high density. The standing waves are generated not only in an input direction of microwave but also in a direction orthogonal to the input direction. Hence, when the blowout outlet is viewed from the front, the areas of plasma with high density and the areas of plasma with low density occur alternately. This phenomenon makes the plasma generated by microwaves difficult to uniformly jet from the entire region of the blowout outlet. In contrast, the dielectric barrier plasma generator of the present invention is of a dielectric barrier type. Since discharge occurs where the voltage applied to gas exceeds its dielectric breakdown voltage, setting the slope of the thickness of the dielectric substrate in a manner in which the voltage applied to gas exceeds its dielectric breakdown voltage in the vicinity of the blowout outlet enables plasma to uniformly jet from the entire region of the blowout outlet.

The above configuration may preferably include a power supply unit having an applied voltage of 3 kV to 20 kV and a frequency of 20 kHz to 150 kHz.