A medical device is disclosed for cutting an object in a living body lumen. The medical device includes a rotatable elongate member, rotating member having a cutting portion cutting the object and disposed on the distal end side of the elongate member for rotating together with rotation of the elongate member； and a distal member having a guide portion disposed on the distal end side of the rotating member with a space left from the rotating member and a supporting portion which supports the guide portion and defines a dimension of the space in an axial direction of the elongate member. The guide portion is disposed at a position at which the guide portion overlaps with part of the cutting portion and exposes part of the cutting portion as viewed from the distal end side of the distal member.
