To provide a compact danger sensing device having high performance and capable of sensing a danger of a person having visual and hearing handicaps or a person staying in a dangerous place while listening to a headphone stereo, informing him/her of a dangerous condition, and giving an alarm to him/her.

A piezoelectric element 1 is used in common as a microphone detecting dangerous sound and a vibration element (vibrator) informing of the dangerous condition. At 'detection mode' in a normal condition, it detects the dangerous sound as the microphone and inputs it into a detector 4 to judge whether it is the dangerous condition or not. If it is the dangerous condition, a selector switch 2 is switched to 'alarm mode' by an output of a timer 5 to apply a drive signal to the piezoelectric element 1 from a drive circuit for a fixed period of time and then return to the 'detection mode' again.