A computerized ultrasonic inspeciton system was developed to inspect small flaws in ceramic pre-combustion chambers of diesel engines for evaluation of their quality. The system comprises a digitalized multi-channel ultrasonic flaw detector, an immersion test scanner, and a minicomputer which controls the movements of multiple transducers and performs the acquisition of inspection data. The scanner is equipped with two sets of scanner arms and a turntable to rotate a ceramic chamber. The five transducers generate ultrasonic pulses and receive flaws echoes from the critical portions of a ceramic chamber. Incremental movements of the transducers and operation of the turntable make a precise search of flaws for the whole chamber, and the locations and the echoes amplitudes of detected flaws are displayed on a CRT. In its application to inspection of ceramic pre-combustion chambers, this computerized inspection system was used and proved to be an useful tool to evaluate flaws in those chambers.