PROBLEM TO BE SOLVED: To provide an ultrasonic sensor capable of superior transmission and reception of ultrasonic waves.SOLUTION: The ultrasonic sensor includes: a sensor array substrate 2 which has an opening 211 a support film 3 which is provided on the sensor array substrate 2 and closes the opening 211 a piezoelectric body disposed on the support film 3, in an inner region of the opening 211 in a plane view from the thickness direction of the support film 3 a first resin portion 52 which forms a first space S1 closed off from the outside space between the first resin portion 52 and the support film 3, in at least a region in which the opening 211 is formed in the plane view, the first resin portion having a contacting portion 522 which faces the opening 211 and is configured to contact with fingers a second resin portion 53 which forms a second space S2 which is closed off from the outside space and communicates with the first space S1 and an ultrasonic-wave transmitting medium 6 which fills the first and second spaces S1 and S2. A flexible portion 532, having lower rigidity than the support film 3 in the film thickness direction, is provided in at least a portion of the second resin portion 53.COPYRIGHT: (C)2015,JPO&INPIT【課題】超音波を良好に受発信できる超音波センサーを提供すること。【解決手段】開口部211を有するセンサーアレイ基板2と、センサーアレイ基板2上に設けられて、開口部211を閉塞する支持膜3と、支持膜3の厚み方向から見る平面視において、開口部211の内側領域に設けられ、支持膜3上に形成される圧電体と、平面視において、少なくとも開口部211が形成される領域において、支持膜3との間で、外部空間から密閉される第1空間S1を形成するとともに、開口部211に対向して、手指に接触可能な接触部522を備える第1樹脂部52と、第1空間S1に連通し、外部空間から密閉される第2空間S2を形成する第2樹脂部53と、第1空間S1及び第2空間S2に充填される超音波伝達媒体6と、を備える。第2樹脂部53の少なくとも一部には、支持膜3の膜厚方向の剛性よりも小さい剛性の可撓部532が設けられる。【選択図】図3