A method of displaying an elastic image according to the present invention includes the steps of measuring ultrasound cross-section data of a cross-section region of a subject while applying compression to the subject 1 (2, 3, 4), determining distortion of tissue in the cross-section region on the basis of the ultrasound cross-section data, generating an elastic image of the cross-section region on the basis of the distortion, displaying the elastic image on a display device (7), setting a plurality of ROIs on the elastic image displayed on the display device, converting the distortion of each ROI into an index value (12), and displays the index value on the display device (8). In this way, the method enables quantitative evaluation of the hardness of body tissue of a region to be diagnosed.