Provided is a highly reliable acoustic wave device wherein deterioration of electrical characteristics due to deformation of a protective cover is suppressed. A method for manufacturing such acoustic wave device is also provided. The acoustic wave device has a piezoelectric substrate 1 propagating an acoustic wave; an excitation electrode arranged on a first main surface of the piezoelectric substrate 1; a columnar outside connection-use electrode 10 electrically connected to the excitation electrode; a protective cover 17 having a hollow accommodating space 8 in which the excitation electrode is accommodated on the first main surface; and a conductive layer 18 connected to the electrode 10 on the protective cover 17.