HEAT TREATMENT DEVICE

PURPOSE:To provide a heat treatment device where a temperature measuring thermocouple which measures the temperature of a semiconductor wafer can easily be replaced. CONSTITUTION:Three conduits, a first, a second, and a third conduit, 50, 51, and 52, are inserted into a reaction tube 20 through the intermediary of conduit support members 53 as supported at a rear flange 22 in a cantilever and freely extractable manner through the processing gas inlet 23 side of the reaction tube 20. A first and a second thermocouple which measure the temperature of the sides of a wafer W are enclosed in the first and second side conduit, 50 and 51, respectively, and a third and a fourth temperature measuring thermocouple which measure the temperature of the front and rear of the wafer W and a fifth temperature measuring thermocouple which measures the temperature of the center of a wafer are enclosed in the center conduit 52.