The present invention generates a transmitted wave image in which the boundary of a tissue is clear, within a short period of time. An ultrasonic imaging device according to the present invention is provided with: a vibrator array which is obtained by arraying multiple vibrators for emitting/receiving ultrasonic waves； an emission unit which transfers an electric signal to at least one of the multiple vibrators so as to cause the electric signal to be converted to an ultrasonic wave so that the ultrasonic wave is emitted to an object； a reception unit which receives reception signals that are electric signals outputted by the respective multiple vibrators having received reflected waves and transmitted waves obtained by the ultrasonic waves being reflected by the object and transmitted therethrough, respectively； and an image generation unit which generates a reflected wave image of a predetermined cross section of the object with use of the reception signals of the reflected waves, and which generates a transmitted wave image of the cross section of the object with use of the reception signals of the transmitted waves. The image generation unit is provided with a reflected wave image boundary detection unit for detecting the boundary of the object in the reflected wave image, and generates the transmitted wave image such that a boundary, in the transmitted wave image, corresponding to the boundary detected by the reflected wave image boundary detection unit is emphasized.La présente invention génère une image d'onde transmise dans laquelle la limite d'un tissu est nette, en une période de temps courte. Un dispositif d'imagerie ultrasonore selon la présente invention est pourvu : d'un réseau de vibreurs qui est obtenu par la mise en réseau de multiples vibreurs pour émettre/recevoir des ondes ultrasonores ； d'une unité d'émission qui transfère un signal électrique à au moins l'un des multiples vibreurs de façon à amener le signal électrique à être converti en une on
