[Object] To provide a measure capable of flexibly changing the posture when inserted into a blood vessel and increasing the storable amount of an excised atheroma. [Solution] An atherectomy catheter 10 has a shaft 11 having an opening 20 in the side wall, a cutter 12 which is positioned near the opening 20 in the internal space of the shaft 11 and which can move in the axial direction 101 of the shaft 11, and a distal end portion 13 connected to the distal end of the shaft 11. The distal end portion 13 has a blade tube 31 connected to the distal end of the shaft 11 by continuing the internal space, a reduced diameter portion 32 connected to the distal end of the blade tube 31 by continuing the internal space, and a distal end tip 33 whose outer diameter is smaller than the outer diameter of the distal end of the blade tube 31, whose distal end 35 side is projected outward from the distal end of the reduced diameter portion 32, and whose proximal end 36 side is extended into the internal space of the blade tube 31 through the internal space of the reduced diameter portion 32.
