To provide an apparatus of supporting evaluation of rigidity for supporting the evaluation of rigidity of a structure in motion, in a simple and detailed manner.

The apparatus 1 of supporting evaluation of rigidity includes a frequency response function means 21 for inputting a frequency response function of a vibration test under free support conditions; a curve fitting means 22 for executing curve fitting of the input frequency response function, an elastic mode separating means 23 for separating the frequency response of 0 Hz, after the curve fitting into each elastic mode; and a mode contribution ratio display means 24 for displaying a mode contribution ratio showing how each elastic mode contributes to deformation of 0 Hz, based on the separation results. The apparatus 1, further, includes an animation display means 25 for displaying the deformation of the structure in each elastic mode as animation.