A composite sheet unit in which a plurality of sintered piezoelectric thin wires are arranged in a uniform direction on a surface of a resin layer is prepared, and a plurality of the same are laminated and integrated so that the sintered piezoelectric thin wires are positioned between the resin layers. Here, a curing resin may be impregnated therein so as to form resin-impregnated-cured portions. Then, the lamination is cut in a direction crossing a lengthwise direction of the sintered piezoelectric thin wires, so that a piezocomposite is obtained. Cut surfaces may be ground. By so doing, it is possible to provide a highly reliable piezocomposite having a fine structure at low cost, and to provide an ultrasonic probe for ultrasonic diagnostic equipment, as well as ultrasonic diagnostic equipment using the same.