An atherectomy catheter has a shaft having an opening in the side wall, a cutter which is positioned near the opening in the internal space of the shaft and which can move in the axial direction of the shaft, and a distal end portion connected to the distal end of the shaft. The distal end portion has a blade tube connected to the distal end of the shaft by continuing the internal space, a reduced diameter portion connected to the distal end of the blade tube by continuing the internal space, and a distal end tip whose outer diameter is smaller than the outer diameter of the distal end of the blade tube, whose distal end side is projected outward from the distal end of the reduced diameter portion, and whose proximal end side is extended into the internal space of the blade tube through the internal space of the reduced diameter portion.
