Provided is an ultrasonic diagnostic device in which drive current of a vibrator is made uniform despite variation among semiconductor processes. The ultrasonic diagnostic device comprises: a vibrator； a drive signal generation unit for generating a drive signal； and a transmission circuit for outputting drive current in accordance with the drive signal so as to drive the vibrator. The transmission circuit is composed of: a vibrator-drive unit which is implemented by a current mirror including a low-voltage transistor and a high-voltage transistor, and of which the high-voltage transistor is connected to the vibrator； and a current source which supplies operation current to the low-voltage transistor of the vibrator-drive unit in accordance with the drive signal. The drive signal generation unit includes: a transmission circuit drive unit replica which has the same configuration as that of the vibrator-drive unit； and a feedback control unit which detects current flowing to a high-voltage transistor of the transmission circuit drive unit replica, and controls the current to be uniform. To the current source for supplying the operation current to the low-voltage transistor of the vibrator-drive unit, the drive signal generation unit supplies, as the drive signal, a signal that is applied from the feedback control unit to a current source for supplying operation current to a low-voltage transistor of the transmission circuit drive unit replica.L'invention concerne un dispositif de diagnostic ultrasonore dans lequel un courant d'attaque d'un vibreur est rendu uniforme en dépit de variations entre des processus semi-conducteurs. Le dispositif de diagnostic ultrasonore comprend : un vibreur ； une unité de génération de signal d'attaque pour la génération d'un signal d'attaque ； et un circuit de transmission pour la délivrance d'un courant d'attaque conformément au signal d'attaque de façon à entraîner le vibreur. Le circuit de transmission est composé : d'une unité de co
