An antenna device includes a ground plane having an edge side, a monopole antenna element that communicates in a first frequency, and that has a first feeding point, a first line that extends from the first feeding point in a direction away from the edge side of the ground plane, and a second line that is coupled to the first line and extends along the edge side, a plurality of dipole feeding elements that communicate at a second frequency higher than the first frequency, and are disposed, with respect to the ground plane, in positions that match the positions of the second line with respect to the ground plane, and a plurality of reflectors that reflect electromagnetic waves radiated by the plurality of feeding elements, and are disposed respectively in correspondence to the plurality of feeding elements between the ground plane and the plurality of feeding elements.