An apparatus as an aspect of the present invention is a factor analysis apparatus that analyzes a relationship between a target event that is a target of factor analysis and an assumed factor of the target event, and includes a similarity calculator, a first influence calculator, and a second influence calculator. The similarity calculator calculates a degree of similarity between a data item included in provided time-series data and the assumed factor. The first influence calculator calculates a first degree of influence indicating a degree of influence of the data item on the target event on the basis of time-series data of the data item and time-series data of the target event. The second influence calculator calculates a second degree of influence indicating a degree of influence of the assumed factor on the target event on the basis of the degree of similarity and the first degree of influence.