A rice cooker or rice steamer is an automated kitchen appliance designed to boil or steam rice. It consists of a heat source, a cooking bowl, and a thermostat. The thermostat measures the temperature of the cooking bowl and controls the heat. Complex rice cookers may have many more sensors and other components, and may be multipurpose.
The term rice cooker formerly applied to non-automated dedicated rice-cooking utensils, which have an ancient history (a ceramic rice steamer dated to 1250 BC is on display in the British Museum). It now applies mostly to automated cookers. Electric rice cookers were developed in Japan, where they are known as suihanki (炊飯器).