Novel methods have been developed concerning voltage contrast image acquisition using the electron beam tester, and concerning fault searching on a VLSI chip, and have been applied to real faults of VLSI devices. The developed voltage contrast image acquisition method has been shown to have acquisition time about thousand times faster than that of the conventional stroboscopic method. The strategy used in searching is that of tracing back upstream of the fault by referring to the voltage-contrast-subtracted image. This strategy is more effective than the conventional dynamic fault imaging (DFI) method where all the images on the entire chip area and all test vectors are acquired. The results showed that the location time was five times or more shorter than using conventional location methods such as electron beam waveform measurement with the aid of a computer aided design (CAD) database.