An ultrasonograph comprising a probe (10) for transmitting/receiving an ultrasonic wave to/from a subject, a transmitting section (12) for supplying a drive signal to the probe (10), a receiving section (12) for receiving a reflection echo signal outputted from the probe (10), image constructing sections (17, 19, 21) for reconstructing a diagnosis image from the received reflection echo signal, a displaying section (25) for displaying the reconstructed diagnosis image, and a control section for controlling the other sections, wherein the rise of temperature of the probe (10) is suppressed by adequately judging whether the probe (10) is left in the air or not. The ultrasonograph further comprises a judging section (22) for judging from diagnosis image information whether or not the probe (10) is left in the air. If the judging section (22) judges that the probe (10) is left in the air, the control section (26) controls the drive signal supplied from the transmitting section to the probe (10) so as to suppress the rise of temperature of the probe (10).