A driving device, including a drive signal generating section configured to variably control a frequency or an amplitude of an application voltage to a vibration member, includes a variable period setting section configured to output a value of a PWM period, the set value being set so that an average value of PWM periods in one target period of the application voltage is one fraction of an integer number of the target period by variably adjusting the PWM periods in an aperiodic manner; a drive waveform information output section; and a variable period PWM signal generating section configured to generate a PWM signal based on the set value of the PWM period output from the variable period setting section and drive waveform information of the application voltage, wherein the drive signal generating section is a digital circuit.