It is an object of the present invention to provide a technique capable of easily extracting a section signal of a specific sub-process. The anomaly detection system includes an extraction unit for extracting a specific subsequence to be an object of anomaly detection from among a plurality of subsequences from a composite sequence included in a monitor signal. The extraction unit determines an optimal warping path from the composite sequence and a reference sequence, which is an example of the composite sequence acquired in advance, by a dynamic time warping method. The extraction unit identifies a start point and an end point of a specific subsequence based on the optimal warping path and the start point and end point of the subsequence of the reference sequence. The extraction unit extracts a specific subsequence based on a start point and an end point of the specific subsequence.