Electron-irradiation-induced gold atom implantation into alpha-SiC and beta-Si3N4 has been studied by ultrahigh voltage electron microscopy (UHVEM). Bilayer films of Au(target atom)/alpha-SiC (substrate) and of Au (target atom)/beta-Si3N4 (substrate) were irradiated with 2-MeV electrons in a UHVEM with the electron beam incident on the gold layer. In the Au/alpha-SiC system, irradiation with 2-MeV electrons first induces amorphization of the alpha-SiC substrate, and then with continued irradiation gold atoms which have been knocked-off from the gold layer by the collision with 2-MeV electrons are implanted into the amorphous SiC substrate. The distribution of gold in amorphous SiC is not uniform and there exists a concentration fluctuation of gold with the average wavelength of a few to several nm. In the Au/beta-Si3N4 system, it seems difficult to implant gold atoms into the beta-Si3N4 substrate by MeV electron irradiation. The ease with which gold implantation into ceramic substrates takes place has been discussed in terms of the chemical constraint effect.