According to the invention, an ultrasonic apparatus for therapeutical use suitable for remedy by the irradiation of an ultrasonic wave low in the degree of convergence using medicine that stays in a disease region, reduces the threshold of cavitation caused by an ultrasonic wave and secondarily generates active oxygen by the acoustic cavitation caused by the ultrasonic wave is provided. The ultrasonic apparatus for therapeutical use is provided with a belt wearable in a position (on the abdomen of a patient) that surrounds a diseased part and unit ultrasonic radiators can be mounted in an arbitrary position of the belt.