HIGH-FREQUENCY RADIATION PLUG

An aim of the present invention is, in a plug for high frequency emission disposed at an end of a casing having an emission antenna, to suppress a high frequency noise emitted from the emission antenna. The present invention is directed to a plug for high frequency emission including a transmission line for transmitting an electromagnetic wave, an emission antenna for emitting the electromagnetic wave supplied via the transmission line, and a casing constituted by a cylindrical shaped conductor, provided with the emission antenna at one end of the casing, and accommodating therein the transmission line extending from the emission antenna toward the other end of the casing. Inside of the casing, a central conductor electrically connected to the emission antenna and an outer conductor spaced apart from and surrounding the central conductor are embedded in an insulator so as to collectively constitute the transmission line, and the outer conductor is disposed in and held in non-contact with the casing.