A partial discharge detection apparatus for detecting partial discharge in a power cable and recognizing an insulation deterioration state of the power cable. A low-speed AD converter converts an analog signal of an AC waveform flowing through a power cable into a digital signal. A high-speed AD converter converts an analog signal of a partial discharge current into a digital signal. The partial discharge is detected based on the maximum value or the sum of a current value obtained from the digital signal of the partial discharge current obtained by the conversion of the high-speed AD converter, for each phase of the AC waveform, which is obtained from the digital signal of the AC waveform flowing in the power cable. The digital signal is obtained by the conversion of the low-speed AD converter.