Image data of a document generated by a key business terminal or a key business server is sent to a database management server, and this image data and the description contents of the document represented by this image data are stored to a freight tracking information database base. Image data and data of the description contents of the document stored in the freight tracking information database are viewed or searched by an authenticated operator who operates a user terminal. Image data representing the progress of transport of goods is sent to the user terminal from the database management server according to the operator's instruction, and an image represented by this image data is displayed by the user terminal.