A capacitive ultrasonic transducer (c-MUT) comprising a silicon substrate and a transducer element which comprises transducer cells, each of which is constituted by a first electrode equipped on the top surface of the silicon substrate, a second electrode placed opposite to the first electrode with a predetermined gap therefrom and a membrane for supporting the second electrode, wherein a trench is equipped between the adjacent transducers and a conductive film is formed in the trench.
