An ultrasonic treatment apparatus comprising: a probe main body which is extended from a proximal direction toward a distal direction along a longitudinal axis, a high frequency supply section configured to supply a high frequency electric power to the probe main body, the probe main body being configured to transmit an ultrasonic vibration from the proximal direction toward the distal direction, thereby performing the vibration including a longitudinal vibration in a vibrating direction parallel to the longitudinal axis; a distal treatment section which is positioned on a distal direction side with respect to a most distal node position positioned most distally among node positions of the longitudinal vibration in the probe main body, the distal treatment section being configured to apply the ultrasonic vibration transmitted through the probe main body to a treated object, and the high frequency supply section being configured to supply the high frequency electric power to the distal treatment section through the probe main body, thereby the distal treatment section becoming a first electrode; a jaw which is openable and closable relative to the distal treatment section, the high frequency supply section being configured to supply the high frequency electric power to the jaw, thereby becoming a second electrode different in potential from the first electrode in a position facing the first electrode so as to pass a high frequency current through the treated object grasped between the second electrode and the first electrode; a probe side facing surface provided in a position facing the jaw in a surface of the distal treatment section so that frictional heat is generated on the probe side facing surface by the longitudinal vibration of the probe main body due to the ultrasonic vibration, and so that the high frequency current flowing through the grasped treated object between the first electrode and the second electrode passes through the probe side facing surface; and a coating portion which is made of a material having electrically insulating properties and having a higher heat resistance than the probe main body, and which coats at least part of a surface other than the probe side facing surface in the distal treatment section so as to prevent the high frequency current from flowing from the first electrode into a biological tissue other than the treated object through the coating portion due to the electrically insulating properties of the coating portion, such that a current density of the high frequency current that passes through the probe side facing the surface and the treated object is heightened, wherein the coating portion is made of a resin, and has a close contact strength of 1.33×10 7 N/m 2 or more between the distal treatment section of the probe main body and the coating portion. a probe main body which is extended from a proximal direction toward a distal direction along a longitudinal axis, a high frequency supply section configured to supply a high frequency electric power to the probe main body, the probe main body being configured to transmit an ultrasonic vibration from the proximal direction toward the distal direction, thereby performing the vibration including a longitudinal vibration in a vibrating direction parallel to the longitudinal axis; a distal treatment section which is positioned on a distal direction side with respect to a most distal node position positioned most distally among node positions of the longitudinal vibration in the probe main body, the distal treatment section being configured to apply the ultrasonic vibration transmitted through the probe main body to a treated object, and the high frequency supply section being configured to supply the high frequency electric power to the distal treatment section through the probe main body, thereby the distal treatment section becoming a first electrode; a jaw which is openable and closable relative to the distal treatment section, the high frequency supply section being configured to supply the high frequency electric power to the jaw, thereby becoming a second electrode different in potential from the first electrode in a position facing the first electrode so as to pass a high frequency current through the treated object grasped between the second electrode and the first electrode; a probe side facing surface provided in a position facing the jaw in a surface of the distal treatment section so that frictional heat is generated on the probe side facing surface by the longitudinal vibration of the probe main body due to the ultrasonic vibration, and so that the high frequency current flowing through the grasped treated object between the first electrode and the second electrode passes through the probe side facing surface; and a coating portion which is made of a material having electrically insulating properties and having a higher heat resistance than the probe main body, and which coats at least part of a surface other than the probe side facing surface in the distal treatment section so as to prevent the high frequency current from flowing from the first electrode into a biological tissue other than the treated object through the coating portion due to the electrically insulating properties of the coating portion, such that a current density of the high frequency current that passes through the probe side facing the surface and the treated object is heightened, wherein the coating portion is made of a resin, and has a close contact strength of 1.33×10 7 N/m 2 or more between the distal treatment section of the probe main body and the coating portion.