Abstract: A mark indicating strictly confidential information is given in a predetermined portion of a manuscript to be transmitted. When the mark is read and the received manuscript is judged to be strictly confidential information at a receiving party (ST41), the received manuscript data is stored in a memory (ST42). When a password is entered, the data stored in the memory is then printed out (ST44) only if the entered password matches a registered password (ST43). Whereby, the strictly confidential documents is transmitted in safety.