Abstract: In an abnormality monitoring apparatus of the present invention, a plurality of detectors (13, 14) are arranged at a plurality of positions in the axial direction of a pipeline (11) to detect respective sound waves (37) propagating from a position (B) of occurrence of abnormality. The aforementioned position is calculated from a sound wave detection time difference between the detectors (13, 14) and position between the detectors (13, 14). The apparatus further includes an abnormal waveform memory unit (28) for storing the waveforms of a plurality of kinds of typical abnormal sound waves generated from abnormality on the pipeline (11). A display device (19) displays, on the same image screen, the abnormal waveform stored in the abnormal waveform memory unit and that of the sound wave detected. It is, therefore, possible for a monitoring personnel to readily identify a kind of abnormality occurred.