The crystallization of [Ga]-MFI was investigated as a function of synthesis time under atmospheric pressure. The molar composition of the reactants was 100SiO(2)-Ga2O3-11Na(2)O-11TPABr-3500H(2)O. The crystallinity of [Ga]-MFI was examined using several analytical instruments, such as XRD, XPS, XRF, FT-IR, solid state NIAS-NMR, and DTG/DTA. (Ga]-MFI was successfully synthesized under atmospheric pressure at 97 degreesC in 72 It. It was found that the nucleation of [Ga]-MFI took quite a long time, but the crystallization took place very fast. It is supposed that the nucleation is the rate-controlling step in [Ga]-MFI synthesis under atmospheric pressure. Consequently, if the induction period of the nucleation can be shortened, it would be possible to synthesize [Ga]-MFI commercially under atmospheric pressure.