A surgical treatment apparatus includes a first unit including a first vibration transmission member and a first holding member, a second unit including a second vibration transmission member, a second holding member, and an elastic member provided between the second vibration transmission member and the second holding member, configured to be deformed in accordance with a relative arrangement of the second vibration transmission member and the second holding member with respect to the axial direction to give the second vibration transmission member an elastic force in the axial direction, and an adjustment coupling mechanism to couple the first unit and the second unit with each other, arrange the first vibration transmission member and the second vibration transmission member coaxially, and adjust a relative arrangement of the first holding member and the second holding member.
