A packaging material for a power storage device has a structure in which at least a base material layer, a first adhesive layer, a metal foil layer provided with an anti-corrosion treatment layer on one surface or both surfaces thereof, a second adhesive layer or an adhesive resin layer, and a sealant layer are laminated in this order. In the packaging material, the sealant layer includes a layer formed of a resin composition that contains 60 to 95 mass % propylene-ethylene random copolymer (A), and 5 to 40 mass % polyolefin elastomer (B) including 1-butene as a comonomer and having a melting point of 150° C. or less.