A parallel resonance frequency can be adjusted in order to stably and securely block different high frequency noises flowing into a line such as a power feed line or a signal line from electric members including a high frequency electrode within a processing chamber. A filter 102(1) coaxially accommodates a coil 104(1) within a cylindrical outer conductor 110, and a ring member 122 is coaxially installed between the coil 104(1) and the outer conductor 110. The ring-shaped member 122 may be a plate body of a circular ring shape on a plane orthogonal to an axial direction of the outer conductor 110 and made of a conductor such as cupper or aluminum and electrically connected with the outer conductor 110 while electrically insulated from the coil 104(1).