From Ohio History Central
In 1955, the Tappan Stove Company, which was located in Mansfield, Ohio, manufactured the first microwave oven for home use. The Raytheon Company had introduced microwave ovens in 1947, but these ovens were as large as a refrigerator and were too expensive for home use. At Raytheon's request, the Tappan Stove Company sought to reduce the size and cost of microwave ovens in 1952. Tappan's 1955 microwave was just twenty-four inches wide and retailed for 1,200 dollars. In 1965, the company manufactured the first combination conventional range and microwave oven, further boosting sales.
Introduction of the home microwave oven dramatically changed home life in the United States. Cooking became much easier and less time consuming. In 2000, an estimated 150 million microwave ovens were in use in the United States. This number was greater than one microwave oven for every family.