Ultrasonic transducer having a plurality of piezoelectric elements arranged in a matrix, and a method for fabricating them. L shaped printed wiring boards are respectively bonded to each arrays of piezoelectric elements arranged in azimuthal direction. The bonding points of the L shaped printed wiring board to respective piezoelectric element are located at edge portion of respective back electrode. The other branch of L shaped printed wiring boards are stretched vertically to the surface of the piezoelectric elements matrix. A backing plate is formed by molding on the back side of the piezoelectric elements matrix leaving the top of the L shaped printed wiring board protruded from the molded surface of the molded backing plate. Such configuration prevents the reflection from the wiring plate of the piezoelectric element. A flexible printed wiring board is provided with wiring pattern having bonding areas positioned corresponding to the matrix of piezoelectric elements. So, the bonding of the printed wiring board to each of the piezoelectric element is easy. After the bonding, the printed wiring board is cut and bent vertically to the matrix surface to form the L shape. The matrix of piezoelectric elements may be cut out from a large size piezoelectric element before the molding of the backing plate or after its molding.