A unit cell for a solid oxide fuel cell is provided with a substrate including a portion having a first porosity, a battery element formed on the substrate and having an electrode layer and an electrolyte layer, and a low porosity layer provided in at least one of the substrate and the battery element to have a second porosity lower than the first porosity. Sizes of a plurality of pores of the low porosity layer falls in a value equal to or less than 10 .mu.m to laminate a part of the battery element on the low porosity layer.