Temperature distribution measuring device and a temperature distribution measuring method

To provide a temperature distribution measuring device and a temperature distribution measuring method which can easily set an appropriate transfer function in accordance with a change in the length of the optical fiber. A temperature distribution measuring device 20 includes a laser light source 21 is optically connected to the optical fiber 24, a photodetector 26 for detecting light backscattered by the optical fiber within 24, the output of the photodetector 26 the measurement temperature distribution of the resulting tentative after performing a correction calculation using the transfer function and a temperature distribution measuring unit 27, the true measured temperature distribution. The temperature distribution measuring unit 27 stores the data of a full-length each and transfer functions which are set for each position in the length direction of the optical fiber 24. Then, the temperature distribution measuring unit 27, when the length of the optical fiber 24 is changed to change the transfer function to be used for correction calculation using the data transfer function. .FIELD 1