A series ofa‐Si:H films has been prepared by rf sputtering in a H2‐Ar gas mixture. To obtain films with different hydrogen content the hydrogen portion of the gas mixture was changed from 0% to 20%. The shear modulus &mgr; was then measured by the frequency of the surface phonon (Rayleigh wave). The stiffnessSand the ultramicrohardnessHwere measured by using a nanoindenter. From the shear modulus &mgr; and the stiffnessS, the Young’s modulusEand Poisson’s ratio &ngr; were calculated. The intrinsic mechanical stress was measured by the bending‐beam method. With increasing hydrogen content of the films, the decrease of Young’s modulus, microhardness, and internal stress are observed.