PURPOSE: To provide an information transfer device which can easily transfer ID information and abbreviated dial information.

CONSTITUTION: The information transfer device consists of an interface box 2 connecting a portable telephone set by a telephone set connection cable 4 and a control part 1 connecting an RS232C cable 3 to the interface box 2. The control part 1 reads and accumulates either ID information or operation information or both of them from a set with a trouble, which is connected to the telephone set connection cable 4, and accumulates it or them, and writes accumulated information into an alternate set when the connection of the telephone set connection cable 4 is recognized to be switched.