In an SOFC, a solid electrolyte layer and an anode are integrated with each other to provide an electrolyte layer-anode assembly. The anode contains a nickel element and a first proton conductor. The first proton conductor is composed of a first perovskite oxide having proton conductivity. The first perovskite oxide has an AXO3-type crystal structure, the A-site containing Ba, the X-site containing Y and at least one selected from the group consisting of Zr and Ce. The nickel element is at least partially in the form of NiO. The anode has a porosity Pa of 10% or more by volume when INi/INiO≤0.1, where INi/INiO denotes a relative intensity ratio of the peak intensity INi of metallic Ni to the peak intensity INiO of the NiO in an XRD spectrum of the anode.