Abstract: A vending system for hot food comprises stacks of food-containing trays of a standard size, a microwave oven whose horizontal dimensions are similar to those of the trays and whose vertical dimension is preferably such as to produce a resonant cavity for the wavelength used, and means for feeding a selected one of the trays into the microwave oven on demand. The radiation is preferably introduced through a waveguide into the top of the tray. Each tray preferably carries heating instructions in machine readable code, e.g. as apertures on lateral extensions of a horizontal flange, and a reading head reads the instructions and adjusts the microwave oven accordingly. The stacks of trays may be held in a rotary magazine and selected by push-buttons.

Abstract: A tray-type food container for food which is to be heated or re-heated in the container comprises both a flat outer lid heat-sealed to a horizontal flange on the tray and a perforated inner lid of substantially rigid and preferably transparent material which is supported on a step in the wall of the tray and is shaped so as to extend above the level of the step and to provide finger holes whereby it may be grasped and removed after the outer lid has been removed. The inner lid may support the outer lid flush with the flange. The flange may have a peripheral groove to form a guide for a knife for removal of the outer lid. The flange may also carry heating instructions in a machine readable code. A vending machine comprising a microwave oven may be provided with means for selecting a container from a number of stacks and with means for reading the coded heating instructions and regulating the energy supply to the microwave oven accordingly.