A mobile phone terminal (1) is provided with an address book table (TLA) storing an address book indicating names and telephone numbers or electronic mail addresses of other parties of communication, a concealed address book table (TLB) generating a concealed character string in which a part or a whole of characters of the names and the telephone numbers or the electronic mail addresses of the other parties of communication is concealed and storing a plurality of the generated concealed character strings, and an address book display process portion (104) displaying, in a real name display mode, a name and a telephone number or an electronic mail address of other party of communication designated by a user based on the address book table (TLA) without concealing characters of the same, and displaying, in an anonymous display mode, the same as the concealed character string in which a part or a whole of the characters is concealed based on the concealed address book table (TLB).