PROBLEM TO BE SOLVED: To provide a medical information system constructed in a medical institution, configured to allow one or a plurality of applications to be utilized under a single system operator, thereby improving user convenience, while allowing the system operator or an application provider to perform marketing activities satisfactorily.SOLUTION: A medical information system includes: a client terminal 1 used by a user a tenanted medical information system 2 installed by a system operator to collect required medical information, on the basis of a user request transmitted from the client terminal 1 over a communication network N, and displaying it on the client terminal 1 along a display layout and an application server 3 which is connected to the tenanted medical information system 2 over the communication network N, and generates medical information required by the user, in response to a request of the tenanted medical information system 2, by use of an application provided by an application provider.
