An ultrasonic generator is provided, in which the control system can easily be changed in accordance with a cleaning application and a cleaning process. The ultrasonic generator according to the present invention, which causes an ultrasonic transducer to oscillate a signal for ultrasonic vibration, includes a programmable multiple control circuit having a signal generation circuit for generating a signal, and an output adjustment circuit for adjusting the output of the signal from the programmable multiple control circuit, wherein the programmable multiple control circuit has a power control circuit electrically connected to the output adjustment circuit, a phase comparison circuit electrically connected to the output adjustment circuit, a frequency control circuit electrically connected to the phase comparison circuit, and a signal modulation circuit electrically connected to the frequency control circuit via the signal generation circuit.