An ultrasound diagnostic apparatus 1 of the present invention is connectable with an ultrasound probe 2X having a c-MUT element 2 whose sensitivity can be controlled according to an applied bias voltage, and includes a DC bias output portion 5, a transmission signal output portion 7, an operation portion 11, and a control portion 10. The control portion 10 controls the DC bias output portion 5 and the transmission signal output portion 7 so as to output an ultrasound transmission signal after applying the bias voltage when an instruction signal instructing the start of transmission is inputted from the operation portion 11, and so as to stop application of the bias voltage after stopping output of the ultrasound transmission signal when an instruction signal that instructs stopping of transmission is inputted from the operation portion 11.
