Extracting a lung field area and a branch structure area from a three-dimensional medical image, dividing a branch structure local area representing a portion of the branch structure area into a plurality of branch structure local sub-areas and estimating a lung field local sub-area in the lung field area functionally associated with each divided branch structure local sub-area based on the branch structure area, obtaining a pulmonary evaluation value in each estimated lung field local sub-area, and displaying, in a morphological image representing morphology of at least a portion of the branch structure local area, the pulmonary evaluation value in each lung field local sub-area functionally associated with each branch structure local sub-area in the morphological image superimposed such that correspondence relationship between the pulmonary evaluation value and the branch structure local sub-area in the morphological image is visually recognizable.