PROBLEM TO BE SOLVED: To provide an ultrasound diagnostic device capable of acquiring more reliable pulse wave information by a relatively small number of times of measurements.SOLUTION: A calculation part of an ultrasound diagnostic device includes a pulse wave measurement part for measuring a pulse wave moving in a blood vessel using an echo signal reflected at two places of a blood vessel wall when a plurality of ultrasonic beams are relatively obliquely applied to the blood vessel in a living body. The pulse wave measurement part acquires a time change between a first echo signal reflected from a side close to a probe of the blood vessel and a second echo signal reflected from a side far from the probe of the blood vessel for each of the plurality of ultrasonic beams, and calculates pulse wave velocity using a time difference in which a change attributed to the pulse wave in each reflection source (measurement point) occurs, and a distance between the measurement points in a blood vessel running direction.SELECTED DRAWING: Figure 2【課題】比較的少ない計測回数で、より信頼性の高い脈波情報を得ることが可能な超音波診断装置を提供する。【解決手段】超音波診断装置の演算部は、生体内の血管に対し相対的に斜めに複数の超音波ビームを照射したときに、血管壁の２か所で反射されるエコー信号を用いて血管内を移動する脈波を計測する脈波計測部を備える。脈波計測部は、複数の超音波ビームについて、それぞれ、血管の、プローブに近い側から反射した第１のエコー信号と、プローブに遠い側から反射した第２のエコー信号との各時間変化を得て、各反射源（計測点）において脈波に起因する変化が生じる時間差と血管走行方向における計測点間距離とを用いて脈波速度を算出する。【選択図】図２
