To provide a vapor generator having high heat efficiency, and to provide a power plant.

Atomic carbon whose diameter is 1 nm or smaller is mixed with water in a water pipe 2. It is used as fuel to efficiently generate vapor from water. The atomic carbon is heated by an electric heater 3 to generate a great amount of mid infrared rays which gives molecular-level violent vibration to the water in the water pipe 2 to generate internal heat. This requires a shorter time than the case of using only external heating until reaching a saturated temperature and achieves high heat efficiency and lower generating cost. With no use of hydrocarbon fuel, the generation amount of harmful gas such as carbon dioxide is suppressed to greatly contribute to environmental measures.