Ultrasonic vibrating electrode (USVE) was used for the voltammetric measurements of a mass-diffusion-controlled reaction and a charge-transfer-controlled reaction by changing the potential scan rate. In the mass-diffusion-controlled reaction, 96 kHz-ultrasonic vibration (USV) significantly accelerated the electrode reaction at an appropriate scan rate of potential and thereby enhanced the sensitivity of voltammetry. This kind of acceleration effect can never be observed in the conventional mechanical stirring around the electrode. It was concluded that the acceleration effect of USV on the electro-redox reaction was ascribed to a significant increase of the mass transport in a region very close to the electrode surface. On the other hand, no acceleration effect of USV was observed in the charge-transfer-controlled reaction at every scan rate of potential. This result suggests that 96 kHz-USV acts mainly as an adiabatic progressive wave, not as an electrostatic modulation of the potential in the electrode reaction.