In a reflection characteristic measuring apparatus 10 and a method for calibrating the reflection characteristic measuring apparatus, multiple standard spectral characteristics, or multiple calibration data based on the multiple standard spectral characteristics are obtained in advance with corresponding reference values relating to an emission characteristic of a light source 21. An optimum standard spectral characteristic or an optimum calibration data is selected from the multiple standard spectral characteristics or the multiple calibration data obtained. A spectral reflection characteristic of a sample is calculated using the selected standard spectral characteristic or the selected calibration data.