An ultrasonic treatment apparatus includes a sheath having an opening at a distal end thereof; an ultrasonic transducer provided at a distal portion of the sheath and generating ultrasonic vibration; an ultrasonic transmission member connected to the ultrasonic transducer at a proximal end thereof, transmitting the ultrasonic vibration, and provided with a treatment part at a distal end thereof; a gripper moving to the treatment part and grasping the part to be treated between the gripper and the treatment part; a link member connected to the gripper and provided on a side of the ultrasonic transmission member; a manipulator part connected to a proximal end part of the link member to open and close the gripper; and a rigid member which the ultrasonic transducer is inserted into and secured to.