Dynamically generating web contents includes an application execution unit for dynamically generating an HTML file, and an HTTP server for receiving an HTTP request and returning an HTTP response including an HTML file generated by the application execution unit. The application execution unit executes a script of the HTML file, and describes information specifying the file in the object without reading the actual file, if an instruction code of the script is a script to display contents of a specific file held in a storage device. The HTTP server identifies a file held in the storage device on the basis of the information, and transmits the file together with the HTML file.