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

An electrolyte sheet for solid oxide fuel cells, the electrolyte sheet including a ceramic plate body having a first main surface and a second main surface, wherein the first main surface and the second main surface include scattered recesses, and the recesses on one or both of the first main surface and the second main surface have an arithmetic average depth of 0.25 μm to 4.0 μm and a number density of one million recesses/cmto 100 million recesses/cm.