An antenna apparatus includes a ground conductor, an antenna element including an antenna that is parallel to the ground conductor and that has a first end portion and a second end portion, a feed line that is coupled to the first end portion of the antenna and that feeds the antenna through the ground conductor, and a short-circuit line that is coupled to the first end portion of the antenna and that electrically short-circuits the antenna to the ground conductor, and a dummy conductor mounted between the first end portion or the second end portion of the antenna and the ground conductor.