PIEZOELECTRIC DEVICE, DRIVING METHOD OF PIEZOELECTRIC ELEMENT, AND LIQUID EJECTOR

PROBLEM TO BE SOLVED: To provide a piezoelectric device having superior durability.SOLUTION: The piezoelectric device 2 includes a piezoelectric element 1 having a piezoelectric body 13 and electrodes 12, 14 applying voltage to the piezoelectric body 13; a drive control means 20 controlling the applied voltage and the applied frequency of the piezoelectric element 1; an outer temperature measuring device 30 measuring the outer temperature of the piezoelectric device 2; an outer humidity measuring device 30 measuring the outer humidity of the piezoelectric device 2; a dew point measuring means 30 finding the dew point of forming dew on the piezoelectric body 13 in a use state of the piezoelectric device 2, based on the measuring results of the outer temperature measuring device 30 and outer humidity measuring device 30, and the relation between the outer temperature and outer humidity acquired in advance, and the dew point forming dew on the piezoelectric body 13; and a piezoelectric body temperature control means 40 controlling the temperature of the piezoelectric body 13 within a controlled temperature range higher than the dew point measured by the dew point measuring means 30 and lower than 80°C.