HEAT TREATMENT METHOD AND HEAT TREATMENT APPARATUS

The semiconductor wafer is preheated at a preheating temperature, and then irradiated with a flash of light from a flash lamp. The upper radiation thermometer measures a temperature of a front-surface of a semiconductor wafer which is raised by irradiation with a flash of light. When the front-surface temperature of the semiconductor wafer measured by the upper radiation thermometer reaches the target temperature, the supply of a current to the flash lamps is stopped to lower the front-surface temperature of the semiconductor wafer. Since the supply of a current to the flash lamps is stopped when the measured temperature of the front-surface of the semiconductor wafer reaches the target temperature, the front-surface temperature of the semiconductor wafer can be accurately raised to the target temperature regardless of the front-surface state and reflectance of the semiconductor wafer.