An ultrasound diagnostic apparatus includes a quadrature detection section configured to perform quadrature detection on reception radio-frequency data generated by a reception circuit to generate complex data (Diq), a frequency analyzer configured to perform a first frequency analysis using a group (S0) of the complex data (Diq) of a set number (Nf) of sample points starting from a first start point and a second frequency analysis using at least one group (S1, ..., S4) of the complex data (Diq) of the set number (Nf) of sample points starting from a second start point that is different from the first start point, and to acquire a spectral signal corresponding to each pixel of a Doppler waveform image based on results of the first frequency analysis and the second frequency analysis, and a Doppler waveform image generator configured to generate the Doppler waveform image using the spectral signal.
