Abstract: A gas filled electric conductor arrangement has an inclined surface (3A) at the bottom side of an electric conductor (3) that is formed by gradually reducing the cross section (D1, D2) of the electric conductor from one insulator spacer (2A) at one side toward another insulator spacer (2B) at the other side. Because of an angle (.theta.) of the inclined surface (3A), the spacing distance between the electric conductor (3) and the bottom surface (1A) of a grounded tank (1) increases depending upon the distance away from one insulator spacer (2A). Thereby, conductive foreign particles (50) are designed to be moved away from the surface of the insulator spacer (2A) and become trapped by a conductive foreign particle (1) disposed at the center bottom surface (1A) of the grounded tank.