An antenna device. The antenna device includes a printed circuit board, a conductive shield, a first connection portion and a second connection portion. The printed circuit board has a feed point and a ground plane insulated from the feed point. The conductive shield surrounds the printed circuit board. The first connection portion is substantially perpendicular to the printed circuit board, electrically connecting the feed point and the conductive shield. The second connection portion is substantially perpendicular to the printed circuit board, electrically connecting the ground plane and the conductive shield.