The present invention provides a manufacturing method suitable for manufacturing, in large amounts, an ionic conductor that is superior in terms of various properties such as ion conductivity. According to one embodiment of the present invention, provided is a method for manufacturing an ionic conductor, said method including: mixing, using a solvent, LiBH4 and a lithium halide represented by formula (1), LiX (1) (in formula (1), X represents one selected from the group consisting of halogen atoms); and removing the solvent at 60-280° C. Ionic conductors obtained with this manufacturing method can be used as, for example, solid electrolytes for all-solid-state batteries.