A liquid-drop spraying device is provided which can perform a stable liquid discharge without making air bubbles produced in the liquid of the pressurized room as well as the amount of liquid supply per unit time is increased. As applying voltage signal to the piezoelectric / electrostriction element of the drive electronics is shown along with the passage of time, the liquid can be flowed into the liquid pressurized room uniformly, and without entrainment of bubbles from the nozzle side by making the initial discharge time constant being larger than the second discharge time constant in the range of a fall time T3 or T4 in which different discharges are in turn performed with discharge time constant and by suctioning the liquid at a slow supply speed from the inlet hole after liquid discharge. On the other hand, as for the liquid having started to move, since the liquid can be rapidly suctioned with the second smaller discharge time constant, the liquid supply can be performed smoothly and a driving period time T5 can be shortened comparing with the case of suctioning the liquid to the last with the initial time constant, thereby enabling a stable and large amount of liquid discharge per unit time period.