A method of forming a polymer nanofiber-metal nanoparticle composite pattern includes forming on a substrate a polymer nanofiber layer comprising polymer nanofibers made from polymers including a heteroaryl group; selectively exposing to UV-ozone a part of the polymer nanofiber layer through an aperture of a mask; selectively removing a part of the polymer nanofiber layer which was not exposed to UV-ozone from the polymer nanofiber layer to form a polymer nanofiber layer pattern; depositing a metal precursor on the polymer nanofiber layer pattern; and reducing the metal precursor into a metal.