A beam steering apparatus may include: a mirror; a refractive index modulation layer disposed on the mirror; a nanoantenna on the refractive index modulation layer; and an insulating layer disposed between the nanoantenna and the refractive index modulation layer, wherein the insulating layer has a thickness distribution in which a first thickness of the insulating layer on a central region of the mirror is less than a second thickness of the insulating layer on an edge region of the mirror, wherein a refractive index of the refractive index modulation layer is modulated to control propagation direction of beam.