The present invention provides a zirconium oxide powder, a method for producing.the same, and a material for thermal spraying. The material for thermal spraying comprises a zirconium oxide powder comprising polyhedral particles each having not less than 6 faces, wherein the zirconium oxide powder has D50 of not less than 5 μm and less than 15 μm and a D90/D10 of less than 3. D10, D50 and D90 correspond to the point where the cumulative mass from the small-particle-diameter side reaches 10%, 50%, and 90% in the cumulative particle size distribution.