An improved surgical apparatus for use in endoscopic surgery having a user interface operatively coupled to an articulating tool assembly via an elongate tubular member. Movement at the articulating tool directly translates movement at the user interface thereby providing intuitive operation of the surgical apparatus. The apparatus is configured such that the range of motion of the articulating tool assembly emulates the range of motion of the human wrist. The improved apparatus is configured to provide precise and controlled movements such as to not endanger the life of the subject and minimizes any errant or unexpected movements or locking experienced in other surgical instruments.