A communication device comprises a first memory which stores telephone
books, each including identification information and a name of a
communication party, a second memory which stores communication
histories, each including a communication time and identification
information and a name of a communication party, a changing device which
changes a telephone book stored in the first memory, and a control device
which, when the telephone book is changed, changes a communication
history stored in the second memory in accordance with a content of
change.