PROBLEM TO BE SOLVED: To provide a pin for forming a hole for inserting an indwelling tube which permits the indwelling tube to be surely repeatedly inserted into the same place of a blood vessel and permits the indwelling tube to be inserted into the same place where the pin indwells without removing the pin even during the period from the indwelling of the pin to the formation of the hole.SOLUTION: The pin 10 for forming a hole for inserting the indwelling tube is intended to form the hole for inserting the indwelling tube and has a cylindrical pin body 30 having an insertion route of the indwelling tube in the interior and percutaneously inserted into a subcutaneous part and made to indwell for a prescribed period and forming the hole, and a valve body 50 arranged in the insertion route and normally blocking the insertion route on the one hand and permitting the indwelling tube to be inserted on the other hand. The pin is structured so as to permit the indwelling tube to be inserted into the insertion route through the valve body 50 while the pin body 30 forms the hole.
