Employing silicon nanoporous pillar array (Si-NPA), a novel silicon micron/nanometer complex systems as reducing substrate, a self-supported, nanostructured gold film was prepared by immersion technique. The microstructure and surface morphology of the film were characterized. Our experiments disclosed that the preparation of the film is a self-stop process. With the exhaustion of Si-NPA, the chemical reducing reaction related with the Au3+ ions occurring in the immersing solution would stop automatically, and the deposited nanostructured gold film would disengage from the substrate to form a self-supported thin film. The formation mechanism of the film is due to the high surface reactivity and strong chemical reducibility of Si-NPA. The elemental composition analysis by energy dispersive x-ray spectroscopy showed that the prepared gold film exhibits strong capability in nitrogen adsorption and storage, which may find potential applications in the technical fields of gas sensors, air separation, nitrogen purification and membrane synthesis of various nitrides.