<；P>；PROBLEM TO BE SOLVED: To provide a catheter and a catheter insertion instrument, capable of making the distal end of the catheter reach a medication target part while evading the important tissue of a blood vessel, a pancreatic duct and a lymph vessel, etc. <；P>；SOLUTION: The catheter 1 includes: a thin and long tubular body 3 having a lumen in the inside； a first puncture needle 2 directly or indirectly attached to the body 3 so as to be slid in the axial direction of the body 3, and separable from the body 3 by being slid from the position of projecting the distal end from the distal end of the body 3 to the proximal end of the body 3； and a second puncture needle 4 directly or indirectly attached to the body 3 so as to be slid in the axial direction of the body 3, having at least one of sharpness and rigidity different from that of the first puncture needle 3, and separable from the body 3 by being slid from the position of projecting the distal end from the distal end of the body 3 to the proximal end of the body 3. <；P>；COPYRIGHT: (C)2011,JPO&INPIT
