PROBLEM TO BE SOLVED: To easily eliminate characteristic deterioration of a piezoelectric element due to a pyroelectric effect. An ultrasonic probe 2 is electrically connected to a piezoelectric element 23 that transmits and receives ultrasonic waves to and from a subject and an I/O electrode 22 provided on the piezoelectric element 23, and inputs the piezoelectric element 23. The I/O signal line 27, through which the drive signal and the reception signal output from the piezoelectric element 23 flow, and the GND electrode 24 provided on the piezoelectric element 23, which is provided with a gap from the I/O signal line 27, are electrically connected. A GND signal line 28 connected thereto and a thermal deformation unit 29 that is deformed by temperature and contacts the I/O signal line 27 and the GND signal line 28 at a predetermined temperature or higher are provided. [Selection diagram] Fig. 4【課題】焦電効果による圧電素子の特性劣化を容易になくすことである。【解決手段】超音波探触子２は、超音波を被検体に送受信する圧電素子２３と、圧電素子２３に設けられたＩ／Ｏ電極２２に電気的に接続され、圧電素子２３に入力する駆動信号及び圧電素子２３から出力される受信信号が流れるＩ／Ｏ信号線２７と、Ｉ／Ｏ信号線２７と間隙を介して設けられ、圧電素子２３に設けられたＧＮＤ電極２４に電気的に接続されたＧＮＤ信号線２８と、温度により変形し、所定の温度以上でＩ／Ｏ信号線２７及びＧＮＤ信号線２８を接触させる熱変形部２９と、を備える。【選択図】図４
