We have recently developed novel periodic nanoporous silicate glass with high structural stability as low-k thin film by spin-coating method. Periodic porous silicate glass films developed so far cause structural shrinkage (10>∼20% or more) by annealing the spin-coated films. In this investigation we adopt vapor-phase TEOS (tetraethoxysilane)-treatment before anneal. Our novel nanoporous film shows little shift of XRD peak position after annealed at 673K, indicating both the ultimate mechanical strength and the minimization of stress in the interface between the prepared film and the underlying substrate. Such a shrinkage-free periodic nanoporous silica film can possess higher VBD (break down voltage) and lower ILeak (leakage current). In this article we estimate structural properties (including information on pores introduced intentionally) by XRD and TEM observation, and electrical properties (dielectric constant, VBD and ILeak) by IV and CV measurement of this special-treated periodic nanoporous silica film. The dielectric constant of the thus prepared periodic porous silica film with silylation after calcination was evaluated to be around 1.8 at 100kHz.