Patent ID: 8133348

Claim:
A plasma generating apparatus, comprising: coaxial conversion means for coaxial-converting a microwave, the coaxial conversion means including: a coaxial introduction section having a generally cylindrical waveguide provided generally coaxially with a central axis of a generally annular ring slot and a core provided near the central axis, the coaxial introduction section propagating the microwave generally parallel to the central axis; and a coaxial conversion section where the microwave propagated through the coaxial introduction section is spread generally perpendicular to the central axis in a cylindrical space provided generally coaxially with the central axis and is guided to the generally annular ring slot through an annular space provided generally coaxially with the central axis, wherein the generally annular ring slot passes the coaxial-converted microwave, a dielectric window propagates the microwave passed through the generally annular ring slot, a plasma is produced by the microwave propagated through the dielectric window, the cylindrical space has a length (A) parallel to the central axis, the annular space has a width (B) perpendicular to the central axis, and the length (A) is generally identical to the width (B).