To provide a tuyere structure for blowing gas into a molten metal vessel, which reduces cratering wear of sleeves and porous refractories and back attack abrasion of surrounding refractories.

The tuyere structure for blowing gas into the molten metal vessel composed of the porous refractory (a) in a gas circulation part and a sleeve refractory (b) for holding it, is characterized in that the sleeve refractory is composed of multiple pipes having an inner tube (c) contacting with the porous refractory and the outer tube (d) surrounding the inner tube (c), and that the thickness of the inner tube (c) is thinner than the overall thickness of the porous refractory, and by a configuration in which the inner tube (c) is oxtered by the outer tube (d).