PROBLEM TO BE SOLVED: To provide a medical instrument that allows a sub-lumen for inserting an operation wire to be easily and accurately formed along an axis line.SOLUTION: A tubular body 10 includes: a wire reinforcing layer 30 that is formed by winding a reinforcing wire 32 around a main lumen 20 a resin sub-tube 40 that is arranged outside the wire reinforcing layer 30 and defines a sub-lumen 42 having a diameter smaller than that of the main lumen 20 and a resin outer layer 50 that contains the wire reinforcing layer 30 and the sub-tube 40. An operation wire 60 is inserted into the sub-lumen 42 in a movable manner and has a tip connected to a distal portion of the tubular body 10. A holding coil 70 is contained in the outer layer 50 and is wound around both the sub-tube 40 and the wire reinforcing layer 30. An end portion 72 of the holding coil 70 has a winding diameter larger than that of an intermediate portion 74.
