Abstract: Ultrasound diagnostic apparatus that receives a reception signal representing the reflection waves from ultrasound probe, includes position specifying section that specifies the depth of detection object inside the subject based on the temporal variation of the reception signal, and position specifying section that specifies the position of detection object in the first direction based on the reception signal generated based on the reflection waves from detection object obtained with the ultrasound beams transmitted at a first angle and a second angle which are different from each other in a transmission direction of the ultrasound beam.

Abstract: An ultrasound probe includes transmission and reception sections, an acoustic lens, and a switch section. The transmission and reception sections include first, second, and third transmission and reception sections, while the second transmission and reception section is centrally positioned, and the first and the third transmission and reception sections are disposed symmetrically at both sides of the second transmission and reception section. The acoustic lens includes first, second, and third lens portions respectively corresponding to the first, the second, and the third transmission and reception sections. The switch section causes, when a traveling direction of the ultrasound is straight ahead, for example, the second transmission and reception section alone to operate, and causes, when the traveling direction of the ultrasound is to be deflected, the first or the third transmission and reception section to operate. The first and the third lens sections have an aspherical shape.