Nanoindentation was performed to study the interfacial delamination of SiN/GaAs film/substrate structures, and to determine the adhesion properties of the interface. A sequential dual-indentation approach was developed and the tests were carefully designed to induce interfacial delamination, but avoid the occurrence of the film's through-thickness fracture or buckling. A clamped circular plate model was used to approximate the elastic deflection of the detached film and hence the delamination area. The Griffith energy balance was then used to compute the energy release associated with the delamination. The energy release rate, Gin, calculated was found to be independent on the testing conditions, which agrees with the fundamental assumption of the Griffith energy concept.