To recover liquid by a stable fixed amount while making a tip finer by forming a helical projecting part whose center is the center axis of a recovery tube on the inner wall surface of the recovery tube inserted to the object (blood vessel or the like) of liquid carriage for sucking the liquid (body fluid for sampling or the like) from the insertion tip part.

This catheter 10 is provided with a supply tube 2 inserted to the blood vessel B for discharging a physiological saline solution from the insertion tip part 21 and the recovery tube 3 for sucking the liquid from the insertion tip part 31. An agitation rod 4 is freely rotatably inserted to the inside of the recovery tube 3 and the agitation rod 4 is rotationally driven by a driving means 5. The rear end part of the supply tube 2 is connected through a positive pressure pump 11 to the storage tank of the saline M and the rear end part of the recovery tube 3 is connected through a buffer member 6 to a negative pressure pump 12. Then, by forming the helical projecting part composed of a coil-like member on the inner wall surface of the recovery tube 3, an internal flow passage is sufficiently secured regardlessly of the deformation of the recovery tube 3.