To provide a method of manufacturing a surface acoustic wave device formed with an insulation film in a wavy of covering interdigital electrodes whereby a loss of the surface acoustic wave device is reduced.

A SiO2 film 14a is formed to regions 18 between electrode finger forming regions 16 spaced on a piezoelectric substrate 10 in its prescribed direction. After forming of the SiO2 film 14a, each electrode finger 12a is formed to the electrode finger forming regions 16. After forming of each electrode finger 12a, a SiO2 film 14b is formed on the electrode fingers 12a and the SiO2 film 14a between the electrode fingers 12a.