adjusted emissivity makes it possible to accurately measure the actual temperature of the substrate 10 after completion of adjustment the temperature of the cleaned substrate 10 can be measured by the radiation thermometer 120 under either of atmospheric pressure and lowered pressure after time t 1 the internal pressure of the decompressing type heater 100 decreases for this period the temperature measured by the contact temperature measuring part 110 is read as a value lower than the actual temperature of the substrate 10 this is because there is the aforementioned gap as shown in fig2 whereby decreases the thermal conductivity of gas after time t 1 therefore the temperature of the substrate 10 measured by the radiation thermometer 120 having the adjusted emissivity is adopted instead of the contact temperature measuring part 110 based on the temperature measured by the radiation thermometer 120 the heating condition of the heater 130 is set furthermore the time at which the temperature of the substrate 10 measured by the radiation thermometer 120 reaches the final target temperature is referred to as t 5 at time t 6 the internal pressure of the decompressing type heater 100 is almost equal to atmospheric pressure the temperature of the substrate 10 is therefore measured again by the contact temperature measuring part 110 after time t 6 the temperature of the substrate 10 may be measured only by the contact temperature measuring part 110 at time t 6 furthermore whether or not the temperature of the substrate 10 measured by the radiation thermometer 120 the measured temperature of the substrate 10 from time t 1 to t 6 was accurate can be checked based on the measured value of the contact temperature measuring part 110 herein the following explanation.