A web application server executes a process appropriately also with respect to an access from a terminal device which was not recognized by the web application when the application was designed. The web application server includes a DLG file storage unit 12 having stored a DLG file in which a business logic of the web application is described in a definition in an abstract representation, a DLG execution unit 13 for using this DLG file and executing a business process of the web application in response to a request from a client, a view specializer 14 for generating a view consistent with attributes of the client with JSP based on a result of the process by the DLG execution unit 13, and a response generation unit 16 for using the view with a JSP file generated at the view specializer 14 to generate and return a response to the client.