A tubular body includes an elongated inner layer that demarcates a main lumen a wire reinforcing layer that is formed by winding a reinforcing wire around the inner layer a resinous elongated sub-tube that is arranged so as to extend along a longitudinal direction of the main lumen outside the wire reinforcing layer and demarcates a sub-lumen having a smaller diameter than the main lumen a resinous outer layer that sheaths the wire reinforcing layer and the sub-tube and a retaining wire. An operating wire is movably inserted through the sub-lumen, and has a tip connected to a distal portion of the tubular body. An operating part is operated to pull the operating wire to bend the distal portion of the tubular body. The retaining wire is sheathed by the outer layer, and winds together the sub-tube and the wire reinforcing layer. In a medical instrument (catheter), the retaining wire is in contact with a peripheral surface of the sub-tube on both an external diameter side and an outer surface of the wire reinforcing layer.