To allow a user of a portable terminal to unintentionally store and manage user data, which is used on the portable terminal, on a server installed on a network.

When executing an application including a memory access associated with user data, a portable terminal establishes communication with a server installed on a network and downloads the user data, which is used in the application, to temporary storage means. The application is executed by using the user data stored in the temporary storage means. Furthermore, in the application, user data that has been modified by the application is uploaded to the server and the user data used by the application is erased when the application ends. The server stores the user data; establishes communication with the portable terminal; and controls the read or write of the user data that is stored according to the portable terminal, in response to a request for downloading or uploading the user data.