Abstract: An energy feed system for microwave ovens includes a rotatable slotted disc (24) arranged within the oven cavity (10) in front of a feeding aperture (22) in a cavity wall (11). The disc is essentially larger than the feeding aperture and is arranged at a small distance from the cavity wall (11) so that a narrow space (42') is formed between this wall (11) and the disc, through which microwave energy can propagate radially outwardly. The disc comprises a number of slots (27-29, 46-51), oriented transversely to their respective radial position vectors and dimensioned so as to serve as antenna elements for radiating energy into the interior of the oven cavity (10). The disc is journalled eccentrically so as to perform simultaneously a rotational and a translational motion and the narrow space between the disc and the cavity wall is also utilized for guiding an air stream to impinge on vanes (30-32, 44, 45) secured to the lower side of the disc so as to cause the disc to rotate in a predetermined direction.