Abstract: A solid oxide fuel cell, a method of producing the same, a fuel cell stack, and a solid oxide fuel battery. The fuel cell including a solid electrolyte layer, a cathode layer formed on one surface thereof and which contains at least Sr, an anode layer which is formed on the other surface of the solid electrolyte layer, and an intermediate layer formed between the solid electrolyte layer and the cathode layer. At least a part of the intermediate layer is an element diffusion prevention layer; the element diffusion prevention layer being formed of a complex oxide containing at least one rare earth element and Zr; and after having been subjected to accelerated heating in air at 1,000° C. for 100 hr, the element diffusion prevention layer has a thickness of 600 nm or more to 2,000 nm or less and a percent Sr coverage of 90% or lower.