High spatial resolution Auger electron spectra and scanning Auger microscope (SAM) images of supported metal catalysts have been obtained in a UHV scanning transmission electron microscope. Ag/α-Al 2O 3 was used as a model catalyst system, where silver was evaporated, in situ, onto polycrystalline alumina carriers. Silver particles, as small as 2 nm in diameter, were clearly revealed in SAM images with high contrast. On large islands, an edge resolution < 3 nm was achieved. Information about surface and bulk properties of supported catalysts can be extracted from images formed with different signals generated from the same area which are obtained simultaneously.