One purpose of this invention is to provide a positive-electrode mixture that takes full advantage of the excellent properties that sulfur has and is suitable for use in a positive-electrode mixture layer in an all-solid-state sodium-sulfur battery that exhibits excellent charge/discharge capacity even when operated at room temperature. Another purpose of this invention is to provide an all-solid-state sodium-sulfur battery provided with a positive-electrode-mixture layer containing the aforementioned positive-electrode mixture. This positive-electrode mixture is characterized by containing (A) an ion-conducting substance that contains 0.2 to 0.55 phosphorus by weight, (B) sulfur and/or a discharge product thereof, and (C) an electrically conductive material. This positive-electrode mixture is also characterized in that component (C) contains an electrically conductive material (C1) with a specific surface area of at least 1,000 m2/g and is further characterized by being used in a positive-electrode-mixture layer in an all-solid-state sodium-sulfur battery.