Abstract: A detection apparatus comprises an acquisition module configured to acquire a plurality of time-series data on a detection target; a setting module configured to set, based on a first time period in which the plurality of time-series data acquired by the acquisition module exist, a plurality of second time periods as inspection ranges; a selection module configured to select a combination of two or more time-series data from among the plurality of time-series data; and a calculation module configured to calculate a correlation coefficient in each of the plurality of second time periods set by the setting module for the combination of two or more time-series data selected by the selection module.