  We report a set of experimental data on local third-harmonic generation at
microwave frequencies (0.5 GHz) in $YBa_2Cu_3O_7$ and Nb films. For local
investigations of the nonlinear response a probe with inductive coupling was
elaborated. The map of the nonlinear microwave response of a $YBa_2Cu_3O_7$
thin film is plotted below $T_c$ with high resolution. The third-harmonic power
is measured as a function of temperature, input power and dc magnetic field at
some areas of the film. The correlation between the depinning current density
${J_p}$ and the nonlinear microwave response is also demonstrated.
