A data processing method includes a step of obtaining scores of time-series data by comparing the time-series data with reference data in order to process time-series data acquired in a substrate processing apparatus having one or more processing units, a step of classifying the scores into a plurality of levels, and a step of displaying an evaluation result screen including a graph showing an occurrence rate of each level of the scores, the number of occurrences of each level, and a graph showing temporal change in the number of occurrences of a worst level of the scores when substrates have been processed through a predetermined method with respect to the processing units. Accordingly, a data processing method through which a state of the substrate processing apparatus can be easily ascertained is provided.