Erosion or corrosion that has been caused during pouring a molten steel through a sliding gate nozzle for continuous casting becomes very serious when a specially treated molten steel such as deoxidized steel with a Ca alloy is applied for continuous casting. Such erosion can be eliminated by partially arranging a zirconia base refractory material on a portion of the inner surface of the nozzle hole. The zirconia base refractory material is composed of more than 53% by weight of partially stabilized zirconia base refractory material having less than 10 mesh grain size, 1 to 7% by weight of metallic silicon powder having less than 100 mesh grain size and 3 to 10% by weight of carbon powder.