The present invention relates to an ultrasonic treatment apparatus that performs treatment on a living tissue by using ultrasonic waves and is intended to provide an ultrasonic treatment apparatus that enables a cavitation state optimal to the treatment of a living tissue. An ultrasonic treatment apparatus includes an ultrasonic oscillator (18) which generates ultrasonic waves, a probe (24) which is connected to the ultrasonic oscillator (18) and transmits ultrasonic oscillations generated by the ultrasonic oscillator (18), and a treatment portion (26a) which is formed on the probe (24) and treats a living tissue by the transmitted ultrasonic oscillations. The treatment portion (26a) includes a cavitation suppressing portion (39) formed to have such a shape that a pressure of a liquid in a vicinity of an external surface of the cavitation suppressing portion is greater than a saturation vapor pressure of the liquid in fluid analysis concerning ultrasonic oscillations in the liquid.
