A data processing method includes: acquiring time series data; acquiring evaluation values; performing classification; and performing extraction. In the acquiring of the time series data, a plurality of time series data acquired by a substrate processing device are acquired. In the acquiring of the evaluation values, the evaluation values of the plurality of time series data are acquired. In the performing of classification, each of the plurality of time series data is classified into one of a plurality of classifications based on the evaluation value. In the performing of extraction, the time series data corresponding to one of the plurality of classifications is extracted as extracted time series data.