PURPOSE: To etch accurately a vapor-deposited gold film with high productivity by masking the film, immersing it in an etching soln. which does not dissolve gold, and applying ultrasonic vibration.

CONSTITUTION: A vapor-deposited gold film is formed on a substrate, and the part of the film not to be etched is masked. The film is immersed in an etching soln. which does not practically dissolve gold such as a soln. of KOH or NaOH, and the etching soln. is vibrated with ultrasonic waves to carry out etching. The etched film is washed and immersed in "Chlorothene", and the mask is stripped off by vibration with ultrasonic waves. By this method a desired fine pattern can be formed in the vapor-deposited gold film.