A metal structure capable of significantly increasing wavelength selectivity and polarization electivity for an incident light, and a production method thereof. First, a solid transparent substrate (glass substrate) (10) is cleaned and dried (S100). The surface of the substrate (10) is spin-coated with a positive electron lithography-use resist solution and then baked, and the resist solution is removed to form a resist thin film (20) on the substrate (10) (S200). A specified pattern is drawn on the resist thin film (20) with an electron beam, and the film is developed, rinsed and dried (S300). Then, metals such as chromium and then gold are formed sequentially on the substrate (10) by sputtering (S400). And, excessive resist materials are removed from the surface of the substrate (10) (S500), whereby metal nano-rod array (40) is completed. The metal nano-rod array (40) has a structure in which many metal nano-rods having their sizes precisely controlled are integrated on the substrate (10) at constant fine intervals and with their directions aligned in one axial direction.