An all-solid-state secondary battery, including: a solid electrolyte layer; a positive electrode layer including a positive electrode active material layer and a first current collector layer; a negative electrode layer including a second current collector layer, the positive electrode layer and the negative electrode layer sandwiching the solid electrolyte layer; and external electrodes connected respectively to the first current collector layer and the second current collector layer, wherein the positive electrode active material layer is formed of an olivine-type active material, wherein the solid electrolyte layer is formed of a phosphate having a NASICON-type structure, and wherein the solid electrolyte layer contains particulate precipitate having an olivine-type crystal structure that includes a same element as an element forming the positive electrode active material layer.