To obtain directivity with plural antenna elements by using inexpensive material and to facilitate the matching of a design and impedance by mounting a dielectric micro strip antenna on a two-layer substrate and arranging a metallic plate having a female screw on the rear face.

A conductor pattern for ground is formed over almost the entire surface of a printed wiring board 11 and a conductor pattern for feeding is formed on a rear face of the board 11. Four pieces of micro strip line antennas 13 are mounted on the surface of the board 11. The conductor pattern for ground of board 11 and a ground electrode of the antenna 13 are connected by soldering, etc., and the antenna 13 is mounted on the board 11. And, the board 11 is fixed to a metallic plate 15 with screws, etc. The plate 15 is, for example, a round shape and a female screw 19 which opens on an outer peripheral plane is fixed to the plate 15.