An all solid state battery having high output performance and a manufacturing method thereof are provided. The all solid state battery of the present invention comprises a negative electrode layer, a positive electrode layer, and a solid electrolyte layer having a lithium ion conductivity. At least one layer of the solid electrolyte, the positive electrode layer, and the negative electrode layer includes a lithium ion conductive crystal and AxByOz (A is one or more selected from the group consisting of Al, Ti, Li, Ge, and Si. B is one or more selected from the group consisting of P, N, and C, wherein 1≦X≦4, 1≦Y≦5, and 1≦Z≦7). The solid electrolyte material to which a preferable sintering additive is added in a predetermined ratio is densified by firing at relatively low temperature in the manufacturing process. The ion conductivity thereof is also high.