Provided are an ultrasound diagnostic device and an image display method, with which a luminosity correction of a cross-section image is carried out in a superimposed region of the cross-section image and an elastic image. An ultrasound diagnostic device comprises: an ultrasound probe (12) a cross-section image configuration unit (20) which configures a cross-section image which is configured by a reflected echo signal which is received via the ultrasound probe (12) an elastic image configuration unit (34) which configures an elastic image on the basis of elasticity information which is computed from the reflected echo signal and an image display unit (26) which displays a superimposed image from the cross-section image and the elastic image. The ultrasound diagnostic device further comprises: a cross-section image correction unit (40) which corrects the brightness of the cross-section image in a superimposed region of the cross-section image and the elastic image.