An initial segment set generation unit (120) generates an initial segment set (F) from training time-series data (S). An initial segment set sorting unit (130) sorts initial segments included in the initial segment set by the order of feature quantities. A sample segment set generation unit (140) generates a sample segment set (E) from the initial segment set. A sample segment set sorting unit (150) sorts sample segments included in the sample segment set by the order of the feature quantities. A search result distance calculation unit (160) calculates a search result distance (Z) for each of test segments by using the sample segment set.