A food amount detector for automatically detecting the amount of a food
placed in a cooking chamber of a microwave oven, a microwave oven
employing the food amount detector, and control method thereof. Output
voltage of a microwave generator is detected while the microwave oven is
driven, and the amount of the food placed in the cooking chamber of the
microwave oven is determined based on the output voltage such detected. In
accordance with the amount of the food such determined, the food is cooked
under the appropriate driving conditions of the microwave oven.
Accordingly, the user does not need to determine the amount of the food by
himself, or set the driving conditions of the microwave oven such as
cooking time, level of microwave energy, etc. As a result, the user finds
it convenient when using this microwave oven, and the food is cooked under
the exact driving conditions set by the microwave oven. Further, since the
price of the parts are inexpensive, the manufacturing cost is reduced, and
manufacturing process is simplified, so that productivity is improved.