An antenna device according to an embodiment of the present invention includes a dielectric layer, a first electrode layer disposed on a top surface of the dielectric layer, the first electrode layer including a radiation pattern, a second electrode layer disposed on a bottom surface of the dielectric layer, and a flexible circuit board connecting the first electrode layer and the second electrode layer with each other along a lateral portion of the dielectric layer. Efficiency of grounding and noise removing may be improved by the flexible circuit board.