Light is irradiated onto a glass substrate of an organic EL element, and the characteristics of an organic film are analyzed. In the sample analyzing apparatus, in such a way that the glass substrate is located on the upper side, the organic EL element is placed on a stage. The light is irradiated towards the glass substrate, and an amplitude ratio and a phase difference which are related to the organic EL element are measured. Also, the sample analyzing apparatus selects a model of a structure corresponding to reflected lights K1 to K3 of the irradiated light and calculates the amplitude ratio and the phase difference. The sample analyzing apparatus compares the measured result and the result calculated from the model, and properly executes the fitting, and determines the best model among the several models and then analyzes the characteristics related to the organic EL element.