Method for producing sulfide solid electrolyte

This method for producing a sulfide solid electrolyte comprises: a step for obtaining a starting material composition by mixing a lithium (Li) element source, a phosphorus (P) element source, and a sulfur (S) element source; a step for obtaining the sulfide by firing the starting material composition; a step for pulverizing a slurry containing a solvent having fluorine atoms and the sulfide; and a step for drying the slurry. The concentration of the sulfide in the slurry is preferably 3% by mass or more and 40% by mass or less. The step for pulverizing the slurry is also suitable for preparing the slurry by dry-pulverizing the sulfide and mixing the dry-pulverized sulfide with the solvent. 本发明的硫化物固体电解质的制造方法具有以下工序：混合锂(Li)元素源、磷(P)元素源和硫(S)元素源而得到原料组合物的工序；对所述原料组合物进行焙烧从而得到所述硫化物的工序；对包含具有氟原子的溶剂和所述硫化物的浆料进行粉碎的工序；以及对所述浆料进行干燥的工序。所述浆料中的所述硫化物的浓度为3质量％以上且40质量％以下是适宜的。对所述浆料进行粉碎的工序为如下工序也是适宜的：对所述硫化物进行干式粉碎，将被干式粉碎的该硫化物与所述溶剂混合来制备所述浆料。