The ultrasonic spray has been regarded as an efficient method for the coating of functional materials on a variety of surfaces for the sake of cost minimization. In spite of these benefits, it is still challenging to control the resultant droplet size and spray pattern that are strongly dependent on the nozzle type. Here, a novel method for the control of an ultrasonic-driven spray for which an electrostatic force is used is presented. The focus is the mechanism and the controllability of the spray under situations wherein both the oscillation and the electric field are applied on the target liquid. Small volumes of a variety of liquids with a varying dielectric constant were excited with an oscillation frequency of 20 kHz and a voltage that is less than 10 kV; in particular, the electric-field strength influenced the amplitude of the excited-liquid surface, the spray angle, and the droplet size; furthermore, the current increased in correspondence to the increasing of the electric field. The phenomena were investigated using a high-speed camera, PIV (particle image velocimetry), and picoammeter. After the increasing of the electric field, the size of the atomized droplet decreased by 41.1 % compared with that of the conventional ultrasonic spray. The uniformity of the sprayed droplets was also improved, as the standard deviation of the size was reduced by 39.6 %. Lastly, it is expected that this method will be advantageous in many applications such as the focusing of fine aerosols and a coating technique for diverse surface types. In this research, silver-nanowire transparent electrodes (Ag-NW TEs) were fabricated using an electric-field-assisted ultrasonic spray. Additionally, the figure of merit (FOM) values were evaluated, and accordingly, the transparent electrode from the conventional ultrasonic spray was compared with that from the electric-field-assisted ultrasonic spray. The FOM changed from 13.4 to 70.7.