An ultrasonic treatment device includes a vibration transmitting section transmitting an ultrasonic vibration to a distal end of an ultrasonic probe, and a hole defining portion extended toward a proximal direction along the longitudinal axis from a distal end portion of the vibration transmitting section and defining a hole-shaped portion inside the vibration transmitting section. The ultrasonic treatment device includes a tube member extended inside the vibration transmitting section and including a tube distal end which is connected to the hole defining portion of the vibration transmitting section at a first node position of the ultrasonic vibration to a distal direction side of a piezoelectric element.
