An ultrasound diagnostic system includes a connection section for detachably connecting an ultrasound device mounted with a capacitive micromachined ultrasonic transducer and an ultrasound observation apparatus provided with a transmission signal generation section that generates a transmission signal to drive the capacitive micromachined ultrasonic transducer, a discharge section for discharging the charge applied to the capacitive micromachined ultrasonic transducer, and a switching section arranged on a signal line between the capacitive micromachined ultrasonic transducer and the ultrasound observation apparatus, wherein when the ultrasound device is set to a predetermined mounting state with respect to the ultrasound observation apparatus, the capacitive micromachined ultrasonic transducer is electrically connected to the transmission signal generation section via the signal line, and when the ultrasound device is detached from the ultrasound observation apparatus, switching of the switching section is performed so as to be a state in which the charge of the capacitive micromachined ultrasonic transducer of the ultrasound device is discharged by the discharge section.