Countertop microwaves are some of the most popular models, and there are many options to choose from. They are quick and easy to install—just plug them in—and you can move them around as needed, making them a top choice for renters. The main downside of countertop microwaves is that they take up valuable counter space, which can be frustrating if you have a small kitchen.
Some current plastic containers and food wraps are specifically designed to resist radiation from microwaves. Products may use the term "microwave safe", may carry a microwave symbol (three lines of waves, one above the other) or simply provide instructions for proper microwave use. Any of these is an indication that a product is suitable for microwaving when used in accordance with the directions provided.
Food and cookware taken out of a microwave oven are rarely much hotter than 100 °C (212 °F). Cookware used in a microwave oven is often much cooler than the food because the cookware is transparent to microwaves; the microwaves heat the food directly and the cookware is indirectly heated by the food. Food and cookware from a conventional oven, on the other hand, are the same temperature as the rest of the oven; a typical cooking temperature is 180 °C (356 °F). That means that conventional stoves and ovens can cause more serious burns.
Microwave ovens are frequently used for reheating leftover food, and bacterial contamination may not be repressed if the safe temperature is not reached, resulting in foodborne illness, as with all inadequate reheating methods. While microwaves can destroy bacteria as well as conventional ovens, they do not cook as evenly, leading to an increased risk that parts of the food will not reach recommended temperatures.
Easily mistaken for a small television, this Whirlpool microwave is perfect for small spaces and can be tucked away into a cramped cabinet, thanks to its curved back. Measuring only 0.5 cubic feet, this countertop microwave is one of the smallest and mightiest we’ve found. Many customers were pleasantly surprised to find that it has a turntable that's still large enough for full-size dinner plates. At 700 watts, this model matches substantial power with a small footprint—but keep in mind it's not going to compete with larger models that feature 1,000 watts or more. Reviewers love how it performs all the basic functions you need, although some wished for a full numeric keypad to enter the time rather than pressing the plus button.
In 1947, Raytheon built the "Radarange", the first commercially available microwave oven. It was almost 1.8 metres (5 ft 11 in) tall, weighed 340 kilograms (750 lb) and cost about US$5,000 ($56,000 in 2018 dollars) each. It consumed 3 kilowatts, about three times as much as today's microwave ovens, and was water-cooled. The name was the winning entry in an employee contest. An early Radarange was installed (and remains) in the galley of the nuclear-powered passenger/cargo ship NS Savannah. An early commercial model introduced in 1954 consumed 1.6 kilowatts and sold for US$2,000 to US$3,000 ($19,000 to $28,000 in 2018 dollars). Raytheon licensed its technology to the Tappan Stove company of Mansfield, Ohio in 1952. They tried to market a large 220 volt wall unit as a home microwave oven in 1955 for a price of US$1,295 ($12,000 in 2018 dollars), but it did not sell well.
The development of the cavity magnetron made possible the production of electromagnetic waves of a small enough wavelength (microwaves). American engineer Percy Spencer is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Named the "Radarange", it was first sold in 1946. Raytheon later licensed its patents for a home-use microwave oven that was first introduced by Tappan in 1955, but these units were still too large and expensive for general home use. Sharp Corporation introduced the first microwave oven with a turntable between 1964 and 1966. The countertop microwave oven was first introduced in 1967 by the Amana Corporation. After Sharp introduced low-cost microwave ovens affordable for residential use in the late 1970s, their use spread into commercial and residential kitchens around the world. In addition to their use in cooking food, microwave ovens are used for heating in many industrial processes.