To safely arrange and hold a tube without hurting the wall of an organ, etc., by arranging a valve in a base side of the single lumen tube and a expandable balloon in its tip side.

A jejunum supply tube fitting device 2 is constituted of a relatively flexible single lumen tube 4, an expandable balloon 6, and a valve 12. The tube 4 is formed of a semi-rigid PVC plastic, etc. The balloon 6 is fitted to the tip 8 of the tube 4 so as to be communicate with the tube 4. The valve 12 is fitted to the opposite side end part 9 of the tube 4, a hollow 14 is formed in its center, and the flexible tube 4 is inserted therein so that the lumen of the hollow 14 is connected with the tube 4 and the balloon 6. This constitution allow the tube 4 to access to the balloon 6. A syringe is fitted to the hollow 14 and water, etc., is fed to the balloon so that it is expanded, surrounds the inside the stomach of a patient, and guides the tube. This constitution can appropriately arrange the jejunum supply tube in the small intestine.