Abstract: This invention is to manufacturing of SOI (Silicon On Insulator) wafer; with respect to manufacturing of SOI wafer, preparation process of silicon wafer with desired thickness (100), deposition of Alumina (Al2O3) as insulator by an ALE (Atomic Layer Epitaxial) method such as ALCVD, ALD, ASCVD, etc . . . (110), bonding of this wafer with another silicon wafer by various bonding methods (120), Cutting of this bonded wafer by various methods of cutting (130), Polishing the surface of the cut wafer (140). For the insulator material, titanium oxide (TiO2) or tantalum oxide (Ta2O5) can be used other than Alumina (Al2O3) and such bonding process can be done by unibonding method and cutting method can be done by Smart Cut process.