A trocar for inserting a surgical instrument in a body, comprises: a pipe including an outer cylinder relatively slidable in an axial direction, and an inner cylinder； a head located on a proximal end of the pipe； a camera that is journaled in a distal end notch of the pipe inner cylinder so as to be turnable between a development state in which the camera turns to the outside of the pipe and a storage state in which the camera is stored inside the pipe； and a coil spring biasing the camera to the development state.
