Ultrasonic probe and ultrasonic treatment apparatus

An ultrasonic probe transmitting an ultrasonic vibration including a longitudinal vibration from a proximal direction toward a distal direction, the ultrasonic probe comprising:

• a probe main body portion having a longitudinal axis continuously passing through a cross section gravity center, a distal end of the probe main body portion being located at one of node positions or near one of the node positions;
• a distal treatment portion forming a region located on a distal direction side with respect to the probe main body portion;
• a probe curved portion provided in the distal treatment portion in a state of being curved with respect to the longitudinal axis toward a first perpendicular direction perpendicular to the longitudinal axis, and having a gravity center located on a first perpendicular direction side with respect to the longitudinal axis;
• a first outer surface extending over a range from the distal treatment portion to a proximal end of the probe main body portion in a state of facing the first perpendicular direction;
• and
• a second outer surface extending over the range from the distal treatment portion to the proximal end of the probe main body portion in a state of facing a second perpendicular direction opposite to the first perpendicular direction,
• wherein a distance from the longitudinal axis to the second outer surface is constant over the range from the distal treatment portion to the proximal end of the probe main body portion,
• a distance from the longitudinal axis to the first outer surface is smaller than the distance from the longitudinal axis to the second outer surface over a range from the distal treatment portion to the distal end of the probe main body portion, and
• the probe curved portion is curved with respect to the longitudinal axis toward the first perpendicular direction side from a state in which a cross section gravity center over the range from the distal treatment portion to the distal end of the probe main body portion is continuously located on a second perpendicular direction side with respect to the cross section gravity center of the probe main body.