THERMAL TREATMENT DEVICE

PROBLEM TO BE SOLVED: To provide a thermal treatment device capable of making an in-plane temperature distribution of a substrate uniform.SOLUTION: A laser light emitted from a laser light emission part 45 and reflected in a partial region of a lower face of a semiconductor wafer W is further reflected by a mirror face 19a of a reflection part 19, and made to arrive at the partial region. The laser light reflected by the semiconductor wafer W can be radiated on the same region again and reused, and therefore, utilization efficiency of the laser light emitted from the laser light emission part 45 can be improved. As a result, a peripheral edge of the semiconductor wafer W that has a tendency such that a temperature is lower than that of a center part can be efficiently heated, so as to obtain a uniform in-plane temperature distribution. Also, the laser light reflected by the reflection part 19 is finally returned to the laser light emission part 45, so as to prevent the laser light from heating an unexpected portion in a chamber.