Abstract: A leakage inspection method for a sealed container in which a liquid of a non-electrolyte is contained for judging whether a defect exists in the container, the method comprising the steps of applying an inspection AC voltage through electrodes from an inspection power source unit; detecting an AC current flowing through the container and the contained liquid by means of a current detector; obtaining a digital value corresponding to an absolute value of the instantaneous value of the detected AC current; successively totaling the digital values during a totaling period having a specific relation to the waveform of the AC current whereby the total value of the digital values corresponding to the absolute values of the respective instantaneous values of the AC current is arithmetically operated and judging that the defect exists in the container when the total value as the value to be judged is larger than a setting value.