A technique that provides: an ultrasonic transducer in which the accurate arrangement of piezoelectric elements and the electric conductive state between electrode layers are reserved and an ultrasonic diagnosis apparatus and an ultrasonic flaw inspection apparatus which use the ultrasonic transducer is provided. According to the technique and a plurality of piezoelectric elements 1, each being a stacked body in which predetermined numbers of piezoelectric layers 2 and electrode layers 3 are alternately stacked and although this has both sides that are substantially flat along a stacking direction, side electrodes 6 to connect the predetermined electrode layers 3 are placed outside both of the sides, are arranged in a direction orthogonal to the stacking direction and wherein an interval holding member 10 having a predetermined thickness is put between the sides ON which the side electrodes 6 of the piezoelectric elements 1 adjacent to each other are formed.
