Electric chemical means is adopted in the invention. Hydrophobic conducting material with surface roughness not larger than 10 Nano is as working electrode, and is as substrate for developing gas bubbles. Control voltage is at least as positive or negative 0.7V. The reaction time is 1 second - 2.5 hour. The invention also discloses device and method for observing and controlling development of gas bubbles in Nano level. The method can produce gas bubbles in Nano level in single component. Changing voltage and reaction time can control size and quantity of gas bubble. Features are: good reproducibility, and easy of operation.