To restrain peeling and crack of a solid electrolyte film by improving adhesion of a fuel electrode of an electrochemical cell with the solid electrolyte film as well as improving electrochemical reaction efficiency in the electrochemical cell.

A base plate for an electrochemical cell 7 is provided with a main body 8 made of a fuel electrode material, a solid electrolyte film 9, and an active layer 16 consisting of cermet of metal particles and solid electrolyte particles. The main body 8 has a porosity of 30 to 50%, the active layer is of a thickness of 3 μm or more and 15μm or less, and an average particle size dm of the metal particles and an average particle size ds of the solid electrolyte film constituting the active layer 16 are 0.5 μm or more and 1.0 μm or less, with dm/ds within the range of 0.8 to 1.2.