Abstract: Nano-porous material SiO₂ aerogels were made by a sol-gel technique using industrial silicon deriVatives E-40 (a kine of polyethoxydisiloxanes) and catalyzed by HF. The influence of some factors such as catalyst, solvent and water on the gelation process is investigated. The microstructure and properties of the silica aerogels are tested by using pore size distribution, TEM and BET techniques. The results show that the catalyst HF greatly effects the velocity of the hydrolysis and condensation of E-40. TEM, BET and pore size distribution show that the silica aerogels have a high inner surface area and the diameter of the skeletal particles is about 10nm while the pore size is 5-30nm.