A capacitive micromachined ultrasonic transducer 111A includes: a silicon substrate 101； an insulating film 102 formed over the silicon substrate 101； a lower electrode 103； insulating films 104 and 106； a cavity 105 constituted by a void formed in a portion of the insulating film 106； an upper electrode 107； insulating films 108 and 114； and a protective film 109. In addition, the insulating film 106, upper electrode 107, insulating film 108 and insulating film 114 above the cavity 105 configure a vibration film 110, and the protective film 109 above the vibration film 110 is divided into a plurality of isolated patterns regularly arranged with a gap 115 having a constant spacing formed therebetween.
