PURPOSE: To execute selection by easily turn-on and turn-off switching of utterance of an operator guidance, by constituting so that turn-on and turn-off of its utterance operation can be set separately to each of plural operator guidances.

CONSTITUTION: In case when a prescribed program is being executed and an operator guidance is uttering, when one key of a key input part 1 is operated, its key operating signal is outputted as a forced stop signal for forcibly stopping the operator guidance which is uttering, and is applied to a voice synthesizing part 7. a voice guidance control part 5 controls turn-on and turn-off of the utterance operation of the operator guidance in accordance with a data which is set by a voice key, an on-key, an off-key and a numerical key. The voice synthesizing part 7 synthesizes a voice and sounds the synthesized voice from a loudspeaker 8. Also, when the forced stop signal is inputted, the opration for synthesizing a voice is stopped.