ELECTROLYTE SHEET FOR SOLID OXIDE FUEL CELL, MANUFACTURING METHOD FOR ELECTROLYTE SHEET FOR SOLID OXIDE FUEL CELL, AND SINGLE CELL FOR SOLID OXIDE FUEL CELL

An electrolyte sheet for solid oxide fuel cells that includes a ceramic plate body having a warpage height of not more than 300 μm, wherein a maximum value among values of 100×Q/L, 100×R/L, and 100×S/Lis not greater than 1, where Q is a maximum difference between a second side Dand a second virtual straight line Vin an X coordinate, R is a maximum difference between a third side Dand a third virtual straight line Vin a Y coordinate, S is a maximum difference between a fourth side Dand a fourth virtual straight line Vin the X coordinate, Lis a length of a virtual rectangle in an X-axis direction, and Ly is a length of the virtual rectangle in a Y-axis direction.