[Issue] To provide a stylet which makes it possible to improve handling while also facilitating insertion of the catheter, and to provide a catheter set having such a stylet. [Means of Resolution] A stylet 20 with a hole and a stylet 30 without a hole comprise, respectively: a stylet main body 21, 31； an engaging part 24, 34； a film-like linking part 25, 35 for linking the stylet main body 21 etc. and the engaging part 24 etc.； and a soft tip end part 26, 36 which is provided at the tip end of the engaging part 24 etc. The engaging part 24 etc. has a tapered tubular shape which can expand and contract thanks to an alternating arrangement of soft parts 24a, 34a and rigid parts 24b, 34b in the peripheral direction. The stylet main body 21 etc. is then pulled rearwards from a state in which the stylet 20 with a hole and the stylet 30 without a hole are assembled with a catheter 10, thereby enabling the engaging part 24 etc. which can engage with the edge of the opening of the catheter 10 to contract in the radial direction and be withdrawn.
