Energy partition of harmonic waves through a micro gap considering frictional contact was investigated. The incident waves were assumed to be strong enough to make the two solids come into contact. Using the Fourier analysis technique and corrective solution superposition method, the nonlinear boundary problem was reduced to a set of algebraic equations. Special examples for identical materials were discussed in detail. The locations and extents of the separation, slip and stick zones and the energy partition are displayed. Moreover, the effects of gap width, coefficients of friction and incident angle are discussed. These relations are quite effective on seismology and civil engineering.