Abstract: A catheter (1) has a distal side and a proximal side and includes a tip part (10) and a main body part (20) disposed proximal to the tip part (10), the main body part (20) includes a first layer (21) and a second layer (22), the first layer (21) contains 60% by mass or more of an ethylene-tetrafluoroethylene copolymer, the second layer (22) is disposed inside of the first layer (21) in a radial direction of the catheter (1) and contains 60% by mass or more of a polyamide resin, and a cantilever bending load of the tip part (10) is smaller than a cantilever bending load of the main body part (20).

Abstract: A catheter (1) has a distal side and a proximal side and includes a tip part (10) and a main body part (20) disposed proximal to the tip part (10), the main body part (20) includes a first layer (21) and a second layer (22), the first layer (21) contains 60% by mass or more of an ethylene-tetrafluoroethylene copolymer, the second layer (22) is disposed inside of the first layer (21) in a radial direction of the catheter (1) and contains 60% by mass or more of a polyamide resin, and a cantilever bending load of the tip part (10) is smaller than a cantilever bending load of the main body part (20).

Abstract: Provided is an in-vivo indwelling tube having a high flap strength and capable of smoothing the passing through a conduit of an endoscope. A method for producing an in-vivo indwelling tube having one end and the other end, the method including the steps of: arranging, in a lumen of the first tubular member, the other end of the second tubular member; joining the first tubular member and the second tubular member; arranging the second tubular member in a lumen of a third tubular member in which an axial length is shorter than the second tubular member; joining the second tubular member and the third tubular member; arranging one end of the second tubular member in a lumen on the other end side of the fourth tubular member including a flap with a base end and a free end; and joining the second tubular member and the fourth tubular member.