A surgical instrument (100), comprising: a housing (112) that includes an elongated rod (116) having a distal part extending therefrom and a proximal part coupled to the housing, the elongated rod having a longitudinal axis defined through； a drive mechanism (122) operatively coupled to the elongated and movable rod with respect to the housing between an actuated position and a non-actuated position to selectively move the elongated rod along the longitudinal axis； a terminal effector (114) that includes a pair of first (130) and second (132) opposing jaw members movable relative to each other from a first position in which the jaw members are disposed in separate relationship with respect to each other another to a second position in which the jaw members cooperate to grab tissue between them as soon as the elongated stem movement along the longitudinal axis occurs, the terminal effector adapted to connect to an electrosurgical energy source (141) for conduct electrosurgical energy through the tissue seized between the jaw members to effect a tissue seal； a switch (136) supported by the housing and mobile between an activated position to start the electrosurgical energy supply from the electrosurgical energy source to the terminal effector and a deactivated position to terminate the electrosurgical energy supply from the electrosurgical energy source to the effector terminal； a switch activating member (138) disposed on the drive mechanism and configured to move the switch to the activated position as soon as the movement of the drive mechanism occurs to the actuated position, and to the deactivated position as soon as the movement occurs from the drive mechanism to the non-driven position； characterized in that the surgical instrument further comprises a switch control member (136a) configured to keep the switch in the activated position during at least the partial movement of the drive mechanism from the driven position to the non-operated position.Un instrumento
