An apparatus for measuring a reference spectrum includes a parameter adjuster configured to adjust a parameter of a spectroscope so that an intensity of a reflection spectrum of a sample has a value in a range, a reference material spectrum measurer configured to adjust reflectance of a reference material so an intensity of a reflection spectrum of the reference material is not saturated, and measure the reflection spectrum of the reference material, using the spectroscope having the adjusted parameter, a first reference spectrum calculator configured to, in response to the adjusted reflectance of the reference material not being one hundred percent, calculate a first reference spectrum based on the measured reflection spectrum of the reference material, and a second reference spectrum measurer configured to measure a second reference spectrum of the reference material, using the spectroscope having the adjusted parameter, when a light source of the spectroscope is turned off.