Trocar

摘要

A trocar (1) is provided with an inner needle unit (2) including an optical observing device (4) and a puncture-assisting device that is provided on an outer peripheral face of the inner needle unit (2) and assists puncture of the inner needle unit (2) into a body cavity, where the puncture-assisting device includes at least one of an ultrasonic energy applying device (81) and an electric energy applying device (82).