To provide a lithium ion battery sheathing material of which an aluminum layer is not short-circuited with an inside electrode, having improved electrolyte resistant property and sufficient life at the circumstance in which the battery is used.

The lithium ion battery sheathing material is composed of a lamination body formed by successively laminating an aluminum foil, an adhesive layer, and a sealant layer on a single-layered or multi-layered base material film. Boehmite treatment and cation electro-coating are applied at least to the adhesive layer side of the aluminum foil.