The present invention addresses the problem of providing an intracorporeal introduction instrument capable of reducing patient and medical practitioner hardship by simplifying surgical procedures and shortening surgery time. An intracorporeal introduction instrument (1), which has grasping sections (3a, 3b) at one end of a pair of rod-shaped members, handle sections (4a, 4b) at the other end, and movement-transmitting sections (5a, 5b) between the grasping sections and the handle sections, respectively, and which opens and closes the grasping sections via the movement-transmitting sections according to the opening and closing of the handle sections. The intracorporeal introduction instrument is characterized in that the movement-transmitting sections form a double lever mechanism, which transmits opening and closing movements of the handle sections as opening and closing movements of the grasping sections.
