A phase shifting device may include a plurality of metal layers and a plurality of first dielectric layers, a metal layer of the plurality of metal layers and a first dielectric layer of the plurality of first dielectric layers being alternately stacked in a first direction, and a second dielectric layer disposed on a side surface of the stacked structure in a second direction, wherein the first dielectric layer includes a first material having a first dielectric constant and the second dielectric layer includes a second material having a second dielectric constant, and wherein the second dielectric constant is greater than the first dielectric constant.