Amorphous silica shows selective hydrogen diffusion at high temperatures. Hydrogen permselective silica membranes prepared by a chemical vapor deposition (CVD) method were reviewed. There are two CVD methods classified by supply directions of silica precursors. One is a one side geometry method which silica precursors are supplied from the one side of a porous substrate. The other is a counter diffusion method which two precursors are introduced from the other side of a porous substrate. Recently, a hydrothermal stable silica membrane was prepared by a counter diffusion method using TMOS and O2 as precursors. Reproducibility of the silica membranes were over 90%.