To provide a highly safe medical tube for reliably administering a nutritional supplement or a medicament into a stomach.

A feeding tube 1 which is inserted into the stomach from a nose of a patient through an esophagus and is used to administer the nutritional supplement includes the body 2 of the tube having a through-hole 21 penetrating through a wall part of a distal end part and a shutter member 3 for opening and closing the through-hole 21. The shutter member 3 includes two ringlike members 31, 32 constituted of a gel polymer which varies a volume depending on properties of a liquid with which the gel polymer makes contact. The feeding tube 1 is inserted when the respective ringlike members 31, 32 are dilated to be in a closed state. Then, when the distal end part reaches the inside of the stomach, respective ringlike members 31, 32 contract by making contact with a stomach fluid, and the through-hole 21 automatically opens. Consequently, a nutritional supplement administering route for reliably administering it into the stomach is formed while the administration of the nutritional supplement into a trachea is prevented.