A method for manufacturing an acoustic wave device with an excellent frequency-temperature profile is performed such that the acoustic wave device produced includes a piezoelectric substrate, an IDT electrode located on the piezoelectric substrate, and a dielectric film mainly including Si and O and arranged on the piezoelectric substrate to cover the IDT electrode. The dielectric film is formed by sputtering in a sputtering gas containing H.sub.2O.

Provided are: a hard lubricating coating film which is hard and has wear resistance; and a hard lubricating coating film-covered tool. A hard coating film (10), which is hard and has wear resistance, and an end mill (12) can be obtained by alternately forming two or more (CraMobWcVdBe)1-x-yCxNy layers A (22) and two or more (CraMobWcVdBe)1-x-y-zCxNyOz layers B (24) by controlling the composition ratios of Cr, Mo, W, V and B and various reaction gases during the film formation, or alternatively by controlling only the various reaction gases during the film formation. In this connection, the atomic ratios a-e, y and (x+y) of the layers A (22) are within predetermined ranges; the atomic ratios a-e, x, y, z and (x+y+z) of the layers B (24) are within predetermined ranges; the film thickness (D1) of the layers A (22) is within the range from 2 nm to 1,000 nm (inclusive); the film thickness (D2) of the layers B (24) is within the range from 2 nm to 500 nm (inclusive); and the total film thickness (D) is within the range from 0.1 m to 10.0 m (inclusive).