PURPOSE: An ultrasonic transducer, an ultrasound probe, and an ultrasound diagnostic apparatus are provided to transmit electric signals to piezoelectric elements through a side surface electrode, respectively, thereby being applied to a two-dimensional arrangement structure and a laminated type structure. CONSTITUTION: An ultrasonic transducer (110) includes a plurality of piezoelectric elements (121), separate electrodes, side electrodes, and a side surface substrate (131). A plurality of piezoelectric elements is arranged in at least one line. The separate electrodes are provided on at least one surface of upper and lower surfaces of each of the plurality of piezoelectric elements. The side surface electrodes extend toward one side surface of the plurality of piezoelectric elements from the separate electrode elements. The side surface substrate is attached to one side surface of the plurality of piezoelectric elements, and has wires electrically connected with the side surface electrodes, respectively.초음파 트랜스듀서, 초음파 프로브, 및 초음파 진단장치가 개시된다. 개시된 초음파 트랜스듀서는, 적어도 하나의 열로 배열된 복수의 압전소자들과, 복수의 압전소자들 각각의 상면 및 하면 중 적어도 어느 일면에 마련된 개별 전극들과, 상기 개별 전극들로부터 복수의 압전소자들의 일 측면으로 각각 연장되는 측면 전극들과, 복수의 압전소자들의 일 측면에 부착되며 측면 전극들과 각기 전기적 접속을 하는 배선들을 구비하는 측면 기판；을 포함한다.
