Providing a medical image storage unit that stores a medical image, an image processing unit that performs image processing on a medical image to be stored in the medical image storage unit and stores the result of the image processing in association with the medical image, and a past medical image identification unit that identifies, at a storage time point of a new storage target medical image in the medical image storage unit or at a time point before the storage time point, a past medical image related to the new storage target medical image from the medical images stored in the medical image storage unit, wherein the image processing unit performs the same image processing as that for the new storage target medical image on the identified past medical image and stores the result of the image processing in association with the past medical image.
