PRODUCTION METHOD FOR SULFIDE SOLID ELECTROLYTE AND PRODUCTION DEVICE FOR SULFIDE SOLID ELECTROLYTE

A method for producing a sulfide solid electrolyte includes: supplying a sulfide solid electrolyte raw material to a tank of a heating furnace; and heating and melting the sulfide solid electrolyte raw material in a gas atmosphere containing a sulfur element. The method includes: obtaining a melt by the heating and melting; and setting a temperature on a bottom side of the melt to be higher than a temperature on a liquid surface side of the melt in the tank.