A structure evaluation system comprising: a plurality of acoustic emission "AE" sensors configured to detect elastic waves generated from a structure and convert the elastic waves into signals; a position locator configured to derive a wave source distribution indicating a distribution of a wave sources of the elastic waves generated from the structure, on the basis of a pre-stored sensor position information and the signals that includes a sensor ID and a detection time; a velocity calculator configured to derive a propagation velocity distribution indicating a distribution of a propagation velocity of the elastic waves based on the elastic waves and information on the installation position of the plurality of AE sensors; and an evaluator configured to: segment the wave source distribution, based on a reference value related to a density of the wave sources, into a region in which the wave sources are sparsely arranged and a region in which the wave sources are densely arranged; segment the propagation velocity distribution, based on a reference value related to the propagation velocity of the elastic waves, into a region in which the propagation velocity is high and a region in which the propagation velocity is low; superimpose a segmented wave source distribution and a segmented propagation velocity distribution; and evaluate the soundness of the structure by evaluating to which of the resulting four phases each superimposed region of the structure corresponds. a plurality of acoustic emission "AE" sensors configured to detect elastic waves generated from a structure and convert the elastic waves into signals; a position locator configured to derive a wave source distribution indicating a distribution of a wave sources of the elastic waves generated from the structure, on the basis of a pre-stored sensor position information and the signals that includes a sensor ID and a detection time; a velocity calculator configured to derive a propagation velocity distribution indicating a distribution of a propagation velocity of the elastic waves based on the elastic waves and information on the installation position of the plurality of AE sensors; and an evaluator configured to: segment the wave source distribution, based on a reference value related to a density of the wave sources, into a region in which the wave sources are sparsely arranged and a region in which the wave sources are densely arranged; segment the propagation velocity distribution, based on a reference value related to the propagation velocity of the elastic waves, into a region in which the propagation velocity is high and a region in which the propagation velocity is low; superimpose a segmented wave source distribution and a segmented propagation velocity distribution; and evaluate the soundness of the structure by evaluating to which of the resulting four phases each superimposed region of the structure corresponds. segment the wave source distribution, based on a reference value related to a density of the wave sources, into a region in which the wave sources are sparsely arranged and a region in which the wave sources are densely arranged; segment the propagation velocity distribution, based on a reference value related to the propagation velocity of the elastic waves, into a region in which the propagation velocity is high and a region in which the propagation velocity is low; superimpose a segmented wave source distribution and a segmented propagation velocity distribution; and evaluate the soundness of the structure by evaluating to which of the resulting four phases each superimposed region of the structure corresponds. <EOS>