The present disclosure provides an ion conductor material that increases the charge-discharge efficiency of a battery. An ion conductor material (1000) according to the present disclosure includes a solid-electrolyte material (101) and a resin binder (102). The solid-electrolyte material (101) includes Li, M, and X. The M is at least one selected from the group consisting of metal and metalloid elements other than Li. The X is at least one selected from the group consisting of F, CI, Br, and I. The molar ratio of a modification group included in the resin binder (102) to the solid-electrolyte material (101) is less than or equal to 0.0002.