provided is a solid electrolyte material provided which , while maintaining a high oxygen ion conductivity , minimizes the extraction of scandia caused by impurities such as silicon in the fuel gas , and has improved intergranular strength in order to eliminate intergranular fracture caused by crystalline modification . the solid electrolyte material is a zirconia solid electrolyte material having yttria dissolved therein , has cubic crystals as the main ingredient , and is further characterized by having a lanthanoid oxide dissolved therein .