In this paper, the nanoporous silicon layer was formed by electrochemical etching of silicon wafer in hydrofluoric acid solution. The purpose of this research, the nanoporous silicon layer were investigated the nanostructure and photoluminescence properties. We report the investigation on nanostructure of nanoporous silicon by using SEM, the gravimetric and fourier transform Raman spectroscopy (FT-Raman) technique. It is found that increasing the constant current density between electrochemical etching have effect to increasing porosity of nanoporous silicon. And increasing porosity of nanoporous silicon is effect from decreasing average size of silicon crystallites in nanoporous silicon which can confirm with Raman spectroscopy. The Changes in the photoluminescence intensity of nanoporous silicon samples are studied during nanoporous silicon stored in various ambient gases such as air, nitrogen, oxigen and vacuum. From data of this experiment when nanoporous silicon were stored in ambient air for a long time, the photoluminescence intensity of nanoporous silicon will decrease. In addition, we found strongly decreasing in its photoluminescence intensity when nanoporous silicon were stored in ambient of oxygen which can confirm by using fourier transfrom infrared spectroscopy (FT-IR) technique.