The present invention provides an inorganic separation membrane including a silicalite nanocrystalline layer formed on a porous ceramic substrate, and a porous inorganic protective layer is formed on the nanocrystalline layer. The crystal grain diameter of the silicalite nanocrystal is preferably 150 nm or less, and the thickness of the silicalite nanocrystalline layer is preferably 1.0 to 4.0 μm. The separation membrane may be manufactured by: immersing a porous ceramic substrate in a dispersion solution of silicalite nanocrystals; laminating the silicalite nanocrystals on the surface of the porous ceramic substrate by evacuating the insider of the porous ceramic substrate; forming a porous inorganic protective layer on the silicalite nanocrystalline layer by a hydrothermal synthesis by heating after immersing the porous substrate in a zeolite synthesis solution containing a silica source; and removing organic components in the silicalite nanocrystal by liquid phase oxidation.