A beam steering device is provided including a p-n junction layer disposed on a reflective electrode layer, wherein a refractive index of the p-n junction layer is variable according to a voltage applied to the reflective electrode layer; a nanoantenna layer including a plurality of components disposed on the p-n junction layer; and a common electrode electrically connected to each of the plurality of components of the nanoantenna. The p-n junction layer may include a p-doped layer and an n-doped layer.