A mist generating device comprising a vibrating plate which vibrates at a high frequency and a liquid supply mechanism for supplying a conductive liquid such as water to the vibrating plate and generating a mist by bringing the liquid supplied through the liquid supply mechanism into contact with the vibrating plate for atomization, the mist generating device further comprising: a liquid-contact detecting unit for detecting presence of contact of the liquid with the vibrating plate; a protective operation performing unit for performing a protective operation for preventing idle vibration of the vibrating plate when the liquid-contact detecting unit detects non-contact of the liquid with the vibrating plate; wherein the liquid-contact detecting unit includes: first and second detecting electrodes (114a, 122) between which the liquid is filled only during a period when the liquid is in contact with the vibrating plate; and a determining unit for determining presence of contact of the liquid with the vibrating plate on the basis of an impedance between the first detecting electrode and the second detecting electrode, and, characterized in that, by giving the same potential to both ends of a series circuit of the impedance between the both electrodes and a pull resistance at non-detection, while giving a known potential difference to the both ends of the series circuit at detection, the impedance is detected through a voltage drop generated in the pull resistance at that time. a liquid-contact detecting unit for detecting presence of contact of the liquid with the vibrating plate; a protective operation performing unit for performing a protective operation for preventing idle vibration of the vibrating plate when the liquid-contact detecting unit detects non-contact of the liquid with the vibrating plate; wherein the liquid-contact detecting unit includes: first and second detecting electrodes (114a, 122) between which the liquid is filled only during a period when the liquid is in contact with the vibrating plate; and a determining unit for determining presence of contact of the liquid with the vibrating plate on the basis of an impedance between the first detecting electrode and the second detecting electrode, and, characterized in that, by giving the same potential to both ends of a series circuit of the impedance between the both electrodes and a pull resistance at non-detection, while giving a known potential difference to the both ends of the series circuit at detection, the impedance is detected through a voltage drop generated in the pull resistance at that time. first and second detecting electrodes (114a, 122) between which the liquid is filled only during a period when the liquid is in contact with the vibrating plate; and a determining unit for determining presence of contact of the liquid with the vibrating plate on the basis of an impedance between the first detecting electrode and the second detecting electrode, and, characterized in that, by giving the same potential to both ends of a series circuit of the impedance between the both electrodes and a pull resistance at non-detection, while giving a known potential difference to the both ends of the series circuit at detection, the impedance is detected through a voltage drop generated in the pull resistance at that time.