Abstract: Provided is a plant data display processing device including: a data classification unit that classifies operation data into categories according to similarity; an evaluation index calculation unit that calculates an evaluation index of a category from a value of the operation data; and a classification result display processing unit that calculates a representative value of the operation data for each of the categories from the operation data contained in each of the categories, maps identification information of each of the categories to two-dimensional space in accordance with similarity of a representative value of the operation data, and generates three-dimensional image data in which the identification information of each of the categories is shown on a plane formed of a first axis and a second axis, and the evaluation index of the category is shown on a third axis.