Reflection spectroscopy

Patent Pending PROBLEM TO BE SOLVED: To highly sensitively detect and quantitatively determine a property change of a measuring object, in reflection spectroscopy. ; SOLUTION: This reflection spectroscopic measuring apparatus of the present invention attains impedance matching by adding a substance B2 of weakening a reflected electromagnetic wave by internal interference to a frequency of an irradiated electromagnetic wave, to a substance A1 of the measuring object, and detects highly sensitively and determines quantitatively the property change of the measuring objective substance A1 when measuring the change as a deviation from the impedance matching.