Provided is a similar case search device which rapidly searches for an appropriate similar case on the basis of plural ROIs.An individual similarity calculation unit sets the ROIs and plural case lesions in a case image so as to be in one-to-one correspondence with each other, compares the feature amounts of the ROIs and the feature amounts of the case lesions which correspond to each other, and calculates an individual similarity for each ROI. A total similarity calculation unit calculates a total similarity for only combinations of completely different types, which are combinations of plural ROIs and plural different types of case lesions in the same case, on the basis of plural individual similarities calculated for each of the plural ROIs. A similar case search unit searches for a similar case on the basis of the total similarities corresponding to the combinations of completely different types.
