Direct observation of the crystal domains of organometal halide perovskite MAPbI(3) (MA: CH3NH3+) was carried out by high resolution transmission electron microscopy (HR-TEM) followed by focused ion beam processing of the sample specimen. The resulting image clearly showed that the linkage of PbI6 octahedron framework is very robust in contrast with methyl ammonium cation. The chemical bonding energy also supported this physical behavior leading to the initial stage of thermal decomposition of perovskite.