The microwave oven was invented by Percy Spencer in 1946 after noticing that the chocolate bar in his pocket was melting as he stood in front of the magnetron that powered the radar he was working with. The first microwave model was not very user-friendly, being nearly 6 feet high and weighing more than 700 pounds.
The microwave had some harsh feedback at first because it wouldn't brown or crisp things. It took until the mid 1960s for the microwave to be improved and reduced in size. The improved cooking and price reduction from between $2,000 and $3,000 down to $500 made it much more accessible to everyday Americans. Today, most homes have a microwave and they are often used daily.