PURPOSE: To digitally display a temperature of a substance whose temperature is measured, by obtaining a ratio of electric signals corresponding to intensity of light beams having 2 differece wavelength, in a light beam radiated from the substance whose temperature is measured, by use of a V/F converter and a counting circuit.

CONSTITUTION: A light beam radiated from a substance T whose temperature is measured is made to pass through 2 kinds of filters f1, f2 whose passing wavelength is different, is amplified H through a photoelectric converting element D, and after that, is inputted to the first and second V/F converters V1, V2 through a separator K and smoothing circuits E1, E2, and is converted to frequency. Also, this color pyrometer is provided with the first counting circuit U1 for generating an output whenever outputs of both these converters V1, V2 are counted by a specified number, the second counting circuit U2 for counting an output of the second V/F converter V2, and an indicator I for displaying the counting contents of this counting circuit U2.