Microwave ovens typically operate at a frequency of 2.45 gigahertz (GHz). This frequency falls within the Industrial, Scientific, and Medical (ISM) radio frequency band. Microwave ovens use this frequency because it is absorbed by water molecules, which allows them to generate heat and cook food efficiently. It's important to note that these frequencies are regulated and allocated by regulatory bodies, such as the Federal Communications Commission (FCC) in the United States, to prevent interference with other wireless devices.