PROBLEM TO BE SOLVED: To provide a technique which can measure the blood vessel diameter accurately by setting the transmission direction of an ultrasonic wave in accordance with the position of a blood vessel.SOLUTION: An ultrasonic measurement device 1 comprises: an ultrasonic measurement control part 210 which transmits an ultrasonic wave to a blood vessel and receives the ultrasonic wave reflected from the blood vessel to create reception data； a blood vessel detection part 220 which detects the blood vessel from the reception data； a transmission direction setting part 230 which sets the transmission direction of the ultrasonic wave for measuring the blood vessel diameter of the blood vessel by using the detection result of the blood vessel position； and a blood vessel diameter measurement part 250 which measures diameter of the blood vessel by transmitting the ultrasonic wave into the transmission direction.【課題】超音波の送信方向を血管の位置に応じて設定し、血管径を精確に計測できるようにする技術を提供すること。【解決手段】超音波計測装置１は、超音波測定制御部２１０が、超音波を血管に対して送信し、前記血管から反射する前記超音波を受信して受信データを生成する。そして、血管判別部２２０が、前記受信データから前記血管を判別し、送信方向設定部２３０が、前記血管位置の判別結果を用いて前記血管の血管径を計測するための前記超音波の送信方向を設定し、血管径計測部２５０が、前記送信方向に前記超音波を送信して前記血管の血管径を計測する。【選択図】図８
