An ultrasonic transducer in which electrodes can be easily and positively joined to a multiplicity of micro-fabricated vibrators and electric wiring can be easily and positively provided. The ultrasonic transducer has a vibrator arrangement having vibrators provided in a predetermined arrangement, each vibrator having first and second electrodes; an interlayer board for holding the vibrator arrangement in which through-holes are respectively formed in positions corresponding to the second electrodes of the vibrators; and a wiring board having a plurality of electrodes electrically connected to the second electrodes of the vibrators through the through-holes formed in the interlayer board, respectively.