An ultrasonic measurement control unit of an ultrasonic measurement apparatus generates received data by transmitting an ultrasonic wave to a blood vessel and receiving the ultrasonic wave reflected from the blood vessel. A blood vessel determination unit determines the blood vessel from the received data. A transmission direction setting unit sets the transmission direction of the ultrasonic wave for measuring the diameter of the blood vessel using the determination result of the blood vessel position. A blood vessel diameter measurement unit measures the diameter of the blood vessel by transmitting the ultrasonic wave in the transmission direction.
