Abstract: A device for applying microwave energy to a product having a microwave cavity defined by a top wall, bottom wall, and opposing sidewalls. The central portion of the microwave cavity contains a conveyer for moving product through the microwave cavity. A waveguide passes through one of the walls of the microwave cavity and directs microwave energy through the mouth of the waveguide which is located in the central portion of the microwave cavity, near the conveyer. The microwave energy is applied directly to the product without the need for antennas, stirring devices, scattering devices, or diffusing devices.