PROBLEM TO BE SOLVED: To provide an acoustic sensor, an ultrasonic probe and ultrasonic diagnostic equipment capable of easily forming a piezoelectric member with high accuracy.SOLUTION: In a semiconductor chip: piezoelectric substance thin films are laminated and disposed directly or indirectly on a semiconductor substrate a state of electric conduction in a prescribed region of the semiconductor substrate changes on the basis of the quantity of electric charge induced by the piezoelectric substance thin films according to acoustic pressure entering the piezoelectric substance thin films and a signal corresponding to the state of electric conduction is output.COPYRIGHT: (C)2016,JPO&INPIT【課題】容易に高精度に圧電部材を形成することが可能な音響センサー、超音波探触子及び超音波診断装置を提供する。【解決手段】半導体基板に対して直接又は間接的に圧電体薄膜が積層配置され、圧電体薄膜に入射した音圧に応じて圧電体薄膜に誘起される電荷の量に基づいて、半導体基板における所定の領域の通電状態が変化し、通電状態に応じた信号を出力する半導体チップを備える。【選択図】図4