Electron-beam deposited Pt emitters were exposed to radical-oxygen gas to remove the surface amorphous carbon layers of the emitters, resulting in observation of fringelike-electron-emission patterns. The superposition of electron-wave interferences due to electrons emitted from a Pt emitter was further observed. These emission patterns were found to be well reproduced by the Fraunhofer diffraction model. These results suggested that the electron-wave interference might take place by electrons emitted from emission sites of Pt nanocrystals. (C) 2009 American Vacuum Society. [DOI : 10.1116/1.3079654]