Examples of the material of the auxiliary starting member 72 include carbon and transition metal compounds. The material of the auxiliary starting member 72 includes a material having a relative permittivity higher than that of the dielectric substrate 12. When the auxiliary starting member 72 is made of a material with a relative permittivity higher than that of the dielectric substrate 12, the material is heated due to its dielectric loss, supplying initial electrons to the space. Carbon is preferable for the material of the auxiliary starting member 72 among other materials. Carbon, which has high thermal stability, prevents evaporation of the auxiliary starting member 72 due to heating or the like after being mounted, thereby enhancing the reliability of the plasma generator 70. The material of the auxiliary starting member 72 may include a material having a low work function that allows electron emission at a lower applied voltage.

Since the plasma generator 70 is provided with the auxiliary starting member 72 in the vicinity of the blowout outlet 30 and on the second surface 13b of the dielectric substrate 12, where the plasma is made to be generated, the initial electrons are supplied to the space in the vicinity of the blowout outlet 30 and on the second surface 13b of the dielectric substrate 12. This eliminates the need for a microwave oscillator with large power capacity and a starter circuit device, thereby providing a compact and inexpensive plasma generator.

The fourth embodiment describes the case in which the protective layer 64 is not provided; however, the fourth embodiment may be configured to be provided with the auxiliary starting member 72 and the protective layer 64.