Metal surface temperature measuring instrument

A metal surface temperature measuring device includes: a container to contain a coolant; a measurement target; a heater to heat the measurement target; a moving mechanism for moving the measurement target; and a thermometer to measure the surface temperature of the measurement target. A main body of the measurement target is formed of silver or copper, and a surface of the main body is coated with a thin film of pure iron or an iron alloy at a thickness of 1 to 100 μm. Further, at least the container, the heater, and the measurement target are disposed in a chamber of an inert gas atmosphere.