There is provided an ultrasonic treatment apparatus, which may treat a part of the body to be treated without use of a medical agent. The ultrasonic treatment apparatus comprises a treatment vessel (11), an ultrasonic element, an ultrasonic element driving circuit, and an operation section (13), wherein the treatment vessel (11) accommodates a medium the ultrasonic element generates ultrasonic waves in the treatment vessel (11), irradiates the ultrasonic waves to the medium accommodated in the treatment vessel (11), and decomposes the water in the medium to thereby generate hydroxyl radicals the ultrasonic element driving circuit drives the ultrasonic element and the operation section (13) is for setting given sterilization conditions determined by the amount of hydroxyl radicals generated by means of the ultrasonic waves. The ultrasonic treatment apparatus sets given sterilization conditions determined by the amount of hydroxyl radicals generated by means of ultrasonic waves, to thereby drastically improve a sterilization effect.
