An information processing device includes: a quality evaluator that evaluates the quality of a plurality of instances of first data to generate a first evaluation result and evaluates the quality of a plurality of instances of second data to generate a second evaluation result; a learner that performs machine learning, using the plurality of instances of first data, to generate a machine learning model for detecting an anomaly; a detector that compares the first evaluation result and the second evaluation result and detects a concept drift, based on a comparison result; and an anomaly estimator that applies the machine learning model to the plurality of instances of second data to estimate whether an anomaly is present in the plurality of instances of second data.