To fit the shape of a general side window glass plate, to make it difficult to disturb a visual field and also to prevent beauty appearance from being damaged by curving a main antenna conductor from the top end of a conductor for phase adjustment downward at prescribed degrees and extending it.

An antenna conductor consists of a main antenna conductor 4a and a conductor 4b for phase adjustment, and the conductor 4b is extended from a feeding point 3 almost horizontally. The conductor 4a is curved at the top end of the conductor 4b at prescribed degrees and is extended. An angle θmade between the conductors 4a and 4b preferably ranges between 70 and 140° and more preferably ranges between 90 to 120° from the viewpoint of sensitivity improvement. The capacitive coupling part 6b of a ground conductor 6 and a side of an automobile front side of a car body open edge 5 are adjacent and are subjected to capacitive coupling. The length of the part 6b of the conductor 6 is ≥45 mm from the viewpoint of sensitivity improvement. It is preferably ≥65 mm and more preferably ≥75 mm.