An automated food vending system includes a vending machine having a plurality of stacks and dispenser mechanisms for dispensing standardized food package units, a microwave oven having a code reader located in a predetermined position in an interior cavity of the oven, and the food package units having standardized shapes corresponding to the vending stacks and to the microwave oven cavity. The food packages have a code for controlling the microwave oven printed in a predetermined position which is readable automatically by the code reader when the package unit is inserted in the oven. The dispenser mechanism has a configuration which allows it to be installed in existing vending machines for canned beverages. It may be fromed as a pair of pivotable holding members spaced apart in the widthwise direction of the holding stack, or as a pair of continuous belts spaced apart in the depthwise direction of the holding stack. The interior of the oven may be shaped to hold two or more different standardized package shapes, and can have a drive element for controllably moving the package past the code reader. The food package is formed with a quadrangular-sided tray portion and a rectangular, laterally projecting lip around the upper edges of the tray portion, and has the code printed extending in a linear direction. Alternatively, the food package unit is formed with a cylindrical shape and has the code printed extending in a circumferential direction.