To provide an ultrasonic diagnostic device which displays a Doppler spectrum image at a desired Doppler velocity range.

An ultrasonic probe 2 and a transmission and reception part 3 transmit and receive ultrasonic waves at a specified pulse repetition frequency to and from a subject to store Doppler signals in a first memory 8. An FFT arithmetic part 11 generates the Doppler spectrum image by executing frequency analysis on the Doppler signals. A display control part 15 causes a display part 17 to display the Doppler spectrum image. When the desired Doppler velocity range is inputted by an input part 18, a processing part 9 reads out the Doppler signals from the first memory 8, and executes a resampling process on the read-out Doppler signals at a sampling frequency corresponding to the desired Doppler velocity range. The FFT arithmetic part 11 generates a new Doppler spectrum image by executing frequency analysis corresponding to the Doppler velocity range. The control part 15 causes the display part 17 to display the Doppler spectrum image.