PROBLEM TO BE SOLVED: To provide an ultrasonic probe including an ultrasonic element of less membrane tension.SOLUTION: An ultrasonic probe includes an element chip 17, and a housing for supporting the element chip 17. The element chip 17 includes a lower electrode 24 formed on a vibrating membrane 43, and a PZT piezoelectric membrane 26 formed on the lower electrode 24. The vibrating membrane 43 has a positive membrane stress, the lower electrode 24 has a negative membrane stress, the PZT piezoelectric membrane 26 has a negative membrane stress, and the sum of membrane tension of the vibrating membrane 43, lower electrode 24 and PZT piezoelectric membrane 26 is positive.COPYRIGHT: (C)2016,JPO&INPIT【課題】膜張力の少ない超音波素子を備えた超音波プローブを提供する。【解決手段】素子チップ17と、素子チップ17を支持する筐体と、を備え、素子チップ17は振動膜43上に形成された下部電極24と、この下部電極24上に形成されたPZT圧電体膜26と、を備え、振動膜43は正の膜応力を持ち、下部電極24は負の膜応力を持ち、PZT圧電体膜26は負の膜応力を持ち、振動膜43の膜張力、下部電極24の膜張力及びPZT圧電体膜26の膜張力を加えた膜張力が正である。【選択図】図4
