An antenna device comprises a dielectric substrate, an antenna including a radiation plate and a ground conductor plate, a connector, and cover member. A position of a feeding point on the radiation plate is different to a position of a centroid of the radiation plate in front view of the antenna, and the antenna and the cover member cover a periphery of the connector when the antenna, the connector, and the cover member are viewed along a direction orthogonal to a first straight line connecting the centroid to the feeding point and orthogonal to a thickness direction of the dielectric substrate.