This paper deals with the influence of ultrasonic field on electric discharge phenomenon, i.e., spark and high-pressure glow discharge. An electrostatic unit having a positive needle electrode and a negative plate electrode was located at the sound pressure node in a standing sound wave field; the sound pressure level and the applied voltage were varied. As a result, the shape of the electric discharge was changed to an open fan-like shape, and the starting voltage for spark and high-pressure glow discharge could be varied by the sound.