Fission barriers of actinides are calculated in the framework of the macroscopic-microscopic method. The single particle energies are obtained within a new version of the Woods-Saxon two-center shell model. A nuclear shape parametrization characterized by five degrees of freedom is used. The barriers are calculated along the minimal action trajectory in the configuration space and the inertia is evaluated within the cranking formalism. The reliability of the model is tested by comparing the theoretical results with values deduced from experimental data.