SOLID a- LITHIUM ELECTROLYTE

(Problem to be Solved) The present invention was made in view of the above-described problems, with an object of providing a Li—P—S-based sulfide solid electrolyte material with both excellent electrochemical stability and a high lithium ion conductivity, providing a method of producing the Li—P—S-based sulfide solid electrolyte material, and providing a lithium battery including the sulfide solid electrolyte material. (Solution) There is provided a sulfide solid electrolyte material including a Li element, a P element, and a S element and having peaks at positions of 2θ=17.90±0.20, 29.0±0.50, and 29.75±0.25′ in powder X-ray diffraction measurement using a Cu-Kαray having an X-ray wavelength of 1.5418 Å, in which assuming that the diffraction intensity of the peak at 2θ=17.90±0.20 is Iand the diffraction intensity of the peak at 2θ=18.50±0.20 is I, a value of I/Iis less than 0.50.