To retrieve a data base without fail and to properly report the retrieved result to a retrieval request source, even if the request source and data base use any character type, respectively, concerning a medical image retrieving device connected to the retrieval request source and a data base, in which a medical image is stored together with character information, for retrieving the desired image from the data base according to retrieval information from the retrieval request source and sending the retrieved result including the character information to the retrieval request source.

The retrieval information received from a retrieval request source 15 or 16 is converted into retrieval information composed of a character type, which is different from a character type to be used for the retrieval request source 15 or 16, to be used for the data base (constructed in image archive devices 17, 18 and 19, for example,) and retrieval is performed. Then, this retrieved result is converted into the retrieved result composed of the character type to be used for the retrieval request source 15 or 16, and sent to the retrieval request source 15 or 16.