Dispersive cathodoluminescence images from thin films of SiO2in a Test‐Element‐Group pattern of a conventional Large Scale Integrated circuit device were observed. Band A (290 nm) and band C (560 nm) of the cathodoluminescence were characteristic of a thermally grown SiO2covered with chemically vapor‐deposited (CVD) SiO2and may be useful for the study of irradiation induced damages in SiO2. Band B (415 nm) and band D (650 nm) were intense in the surface CVD SiO2and may provide information on process induced impurities in SiO2layers. The spatial resolution of a cathodoluminescence image is 2 &mgr;m, and it is possible to survey SiO2layers on a conventional LSI device with this technique.