An antenna device including: a ground plane; an antenna pattern overlapping the ground plane with respect to a first direction; a dielectric layer interposed between the ground plane and the antenna pattern; a feed via coupled with the antenna pattern and penetrating at least a portion of the dielectric layer; a ground via connected to the ground plane and penetrating at least a portion of the dielectric layer; and a ground pattern extending from the ground via and disposed adjacent to a lateral surface of the feed via in a second direction that forms a predetermined angle with the first direction.