Abstract: This paper presents a new type of waveguide discontinuities-inductive septa windows deposited on a dielectric substrate. A formulation for the equivalent circuit parameters of the discontinuities with superior convergency is derived by the transverse resonance method with the singular integral equation technique. As an example, an inductive bilateral septa window is computed. When the configuration is degenerated into an inductive all metal window with zero thickness, the numerical results are in good agreement with the available data in Literature[1].