To eliminate the labor of making a note during a telephone call by extracting important character information from character information where sound information of a transmitted and a receiver are recognized and storing it as the note.

Since a calling sound rings by a telephone function part 8, a user takes up a handset 1. For showing that a note generation function operates to the user in operation of the note generation function, the message of 'note function is in operation' is displayed on a display part 3. When the user does not depress the 'note stop' key of an input part 2, a call is made in the same way as a regular telephone set by leaving the note function in an operation state as it is. Since the note function is in the operation state, a system digitizes sound during the call and preserves it in a memory 5. A point is judged and extracted from a call content and the note is generated. Thus, important character information stored in the memory 5 is displayed on the displayed screen of the display part 3.