A terahertz wave detection device which includes an absorption portion which absorbs a terahertz wave and generates heat and a conversion portion which converts the heat generated by the absorption portion into an electric signal, wherein the absorption portion includes a dielectric layer, a plurality of metal structures which are provided on one surface of the dielectric layer and are arranged to be separated from one another by an interval having a predetermined length; and a metal layer which is provided on the other surface of the dielectric layer, and wherein the interval is shorter than a wavelength of the terahertz wave which is absorbed by the absorption portion.