To warn it to the user that a DP/PB mode is not set by facilitating the setting operation of the DP/PB mode and decreasing the necessity of its re-setting even on the occurrence of a power failure.

When a 'talk key' of a key board 26 of a slave set is depressed while depressing a '#' key or a '*' key, DP/PB mode data comprising a DP or PB code are generated from a control circuit 23 and stored in a memory 24. A control circuit 13 of a master set transfers the DP/PB data stored in a memory 14 to the control circuit 23 via terminals T1+, T2+ and data from the master set are stored in the memory 24 when the DP/PB data are not stored therein. Then data stored in the memory 24 are sent from an antenna 21 and stored in the memory 14, and since the same data are stored in the two memories, even when the data of the one memory are volatile, the data are recovered by transferring the data of the other memory to the one memory. When the 'talk key' is depressed in a talking state and the DP/PB data are not stored in the memory 24, a notice signal generating circuit 27 raises a warning to warn the user.