PURPOSE: To decrease the number of circularly polarized wave element antennas by adopting a conical antenna for the circularly polarized wave element antenna so as to improve the gain of the circularly polarized wave element antenna single body thereby reducing the production of a side lobe.

CONSTITUTION: A conical antenna 1 being a circularly polarized wave element antenna is made up of a conical spiral section 3 obtained by winding a lead wire on a conical face and a linear feeding coupling section 2 formed to an end of a conductor wire wound to form the conical spiral section 3. Then the conical antenna 1 is fixed and supported to a flat plate 11 by inserting the feeding coupling section 2 through a dielectric body 22 fitted to a small hole 14 of a metallic flat disk 11. A feeding power fed from a probe 17A at a feeding end of a coaxial line 16 is coupled and absorbed by the feeding coupling section 2 of the conical antenna 1 while being propagated through an internal space of the a parallel metallic flat plate comprising flat plates 10,11 in a radial direction sequentially and branched to excite the conical antenna 1.