The utility model discloses a guiding tube can keep the intensity in the region of being inserted the body cavity to can carry out accurate puncture operation. Guiding tube (100) have: pipe main part (10), it has lumen (20) and is inserted in the body cavity in inside, puncture opening (30), it communicates with the outside of lumen (20) and pipe main part (10), puncture opening end surface (40), it extends and marks off puncture opening (30) in front end cardinal extremity direction of a tub main part (10), at the axle center X's for a tub main part (10) extending direction sectility and the cross section that forms perpendicularily, the opening angle ( theta ) who becomes with two line segment (14) of tip (16) of the axle center X side of will puncture opening end surface (40) and the binding of axle center X is lighter than 180 degrees, and the direction composition of the opening direction (II) that puncture opening end surface's (40) normal line (I) contains, the direction composition that is greater than the opening direction (II) of puncture opening (30) that the plumb line contained of line segment (14).
