In order to investigate the microstructure of newly developed automobile exhaust catalysts thin cross-sections were prepared by an ultramicrotome and observed by a transmission electron microscope. The observed results demonstrated that the tansmission electron microscopy studies coupled with the ultramicrotomy technique were very useful to characterize the distribution and morphology of the supports active phase metals and additive oxides produced by different conditions/ Moreover from the result of a high-voltage high-resolution electron microscope image of thin sections of catalysts analyzed by the digital Fourier diffractograms it is found that various fine oxides particles composed of a catalyst can be separated on the atomic scale