PURPOSE: To provent an adverse effect from being given to a print circuit element due to the adhesion of dust, by taking coaxial construction from an RF output terminal to a rod antenna feeding point.

CONSTITUTION: A projection 10b is coaxially extended to the lower end of the outermost sleeve 10a of an antenna base 10 consisting of a plurality of sleeves constituted freely extendably and contractably, and is provided with a lug terminal 10c connected to an RF leadwire. This sleeve 10a constitutes a part of a rod antenna feeding section. The lower end of the sleeve 10a is provided with a bracket 16, which is provided with a screw hole 18 for fitting. Thus, the sleeve 10a is suitably grounded to a casing of a device. Thus, the conditions against matching and parastic oscillation can be improved.