To prevent the occurrence of a short-circuit between arms caused by soldering by providing a land being a feeding point for an arm of a side A to the side A and providing a land being a feeding point for an arm of a side B to the side A via a throughhole of a double side printed circuit board from the arm of the side B.

The antenna is provided with a printed circuit board (spiral board) 1 on which two arms 1c, 1d for the antenna are etched, lands 1a, 1b being feeding points to the arms, a printed circuit board (feeding board or balun) 2 on which other feeding patterns 2a, 2b are etched, and a feeding wire 5 connecting and soldered to the lands 1a, 1b of the spiral board 1 and other feeding patterns 2a, 2b of the feeding board 2 respectively. In this case, the two arms 1c, 1d are etched to the front side and the rear side of the spiral board 1 and only the arm 1c and the lands 1a, 1b of one antenna only are etched to one side (front side).