Porous silicon (PS) layers were formed on p-type silicon (Si) wafers by using electrochemical etching method. The influence of varying etching time in the anodizing solution ,on structural and optical properties of porous silicon has been investigated. Additionally , the thickness and porosity of the layers were measured using the gravimetric method. The surface morphology was studied by Scanning Electron Microscope (SEM). Finally, the optical properties of porous silicon on silicon substrates were investigated by employing photoluminescence (PL).