To stabilize filter characteristics and improve the reliability in an elastic wave device.

An elastic wave device includes a piezoelectric substrate 10, a comb-shaped electrode 12 formed on the piezoelectric substrate 10, and an insulative film 16 formed on a surface of the comb-shaped electrode 12 by using Atomic Layer Deposition (ALD) method and including aluminum oxide. A manufacturing method of the elastic wave device includes a process where the comb-shaped electrode 12 is formed on the piezoelectric substrate 10 and a process where the insulative film 16 including aluminum oxide is formed on the surface of the comb-shaped electrode 12 by using ALD method. The insulative film 16 is formed by ALD method, thereby stabilizing filter characteristics and improving the reliability.