Provided is a similar case search device that can perform a similar case search in which attention is paid to the feature amounts of a plurality of regions of interest.A feature amount calculation unit acquires the feature amount of each of a plurality of regions of interest (ROI), each of which is designated so as to include one or more different target lesions (OL) that are lesions in examination images, in examination data including one or more examination images. An individual similarity calculation unit compares the feature amount of each region of interest (ROI) with a feature amount of a case lesion (CL), which is a lesion in a case image registered in a case, and calculates an individual similarity for each region of interest (ROI). A similar case search unit searches for a similar case on the basis of a plurality of calculated individual similarities.
