It is an object of the invention to provide sulfide solid electrolytes having good processability at the time of manufacturing a battery and high ionic conductivity. The present invention relates to a sulfide solid electrolyte containing lithium, phosphorus and sulfur, having a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα rays, and the half-value width of at least one peak obtained by separating the peaks observed in a range of 60 to 120 ppm in solid-state 31P-NMR measurements is 500 to 800 Hz.