PROBLEM TO BE SOLVED: To enable extension of a storage period of medical information likely to be referred to.SOLUTION: A medical diagnosis device according to an embodiment comprises: a storage part that stores medical information a medical information designation part that designates medical information on a past examination having incident information matching or similar to the medical information on a latest examination with respect to the incidental information on a prescribed kind of the medical information, out of the medical information on the same patient stored in the storage part and a storage period extension instruction part that instructs a medical information process device so as to extend a storage period of the medical information on the past examination designated by the medical information designation part.
