PURPOSE: To improve the operability and to facilitate assembly by allowing the base end part of an antenna element fitting plate to bite into the core a feeder line fitted to a base, and connecting the core with an antenna element electrically through a fitting plate.

CONSTITUTION: The tip part of the feeder 7 is inserted into the feeder fitting hole 5b of the base, the endmost part of the core 7a of the feeder 7 is set facing the opposite end part of a fitting groove 5a, and a set screw 8 is inserted threadably from the top surface of the base 5 to position and fix the feeder 7 to the base 5. In this state, the antenna element 1 is fallen down to project the upper end of the fitting plate 3, and the engagement part 3a of the fitting plate 3 is pressed and fitted in the fitting groove 5a of the fitting plate 3 from above. In this case, the endmost part of the core 7a of the feeder 7 is positioned in the reversely V-shaped gap 3f between biting projection pieces 3e of the fitting plate 3, and part of the biting projection piece 3e bites into the tip part of the core 7a, which is then fixed to the base 5 and also connected electrically to the antenna element 1.