PURPOSE: To enable setting a thermometer at the place of a high temperature and with corrosive gas in a combustion chamber, by letting cooling medium flow in the annular space formed between outer and protection tubes, far protecting the protection tube from the high temperature and external atmosphere.

CONSTITUTION: The high temperature corrosion resistance thermometer 1 consists of a temperature sensing element 13 set at a tip part and a protection tube 12 in which a thermocouple measuring the temperature of the temperature sensing element 13 is inserted. An outer tube 15 for forming annular space 14 where cooling medium A flaws, is provided around the protection tube 12.