TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The gas barrier base material further contains an overcoat layer (O) laminated on vapor deposition layer (V). The primer layer (P) for soft vapor deposition contains non-crystalline polyester polyol and/or its isocyanate extension material (P1) and crosslinking agent (P2), and further contains polyol (P3) which is incompatible with polyol (P1) and organosilane of formula (I) or its hydrolyzate and/or metal alkoxide of formula (1) or its hydrolyzate. The polyol (P3) consists of acrylic polyol and/or carbonate polyol. The crosslinking agent is isocyanate compound, carbodiimide compound, phosphorus-type compound and/or transition metal-type compound of formula (1). The primer layer (H) for hard vapor deposition contains components (H1-H3). The component (H1) is polyester polyol, or its isocyanate extension material, acrylic polyol or its isocyanate extension material and/or carbonate polyol or its isocyanate extension material, in which, while using acrylic polyol or carbonate polyol, the component (P3) and (H1) are same. The component (H2) is an isocyanate compound, carbodiimide compound and/or transition metal-type compound of formula (1) or its hydrolyzate. The vapor deposition layer (V) consists of magnesium oxide, silicon oxide and/or aluminum oxide having thickness of 5-300 nm. The overcoat layer contains water soluble polymer and organosilane of formula (I) or its hydrolyzate, metal alkoxide of formula (1) and/or phosphorus type compound. The organosilane is of formula: R-Si(OR')3 (I). The metal alkoxide is of formula: M(OR')n (1).R=alkyl, (meth)acryloyl group, vinyl, amino, epoxy or isocyanate;R'=alkyl group;M=metal ion;andn=valence of the ion.Preferred Property: The polyester polyol (P1) and polyol (P3) have glass transition temperature of less than 40 degrees C. Preferred Composition: The primer layer contains polyester polyol (P1) and polyol (P3) in the mass ratio of 99/1-50/50. The ratio of sum of polyester polyol (P1) and polyol (P3) with respect to crosslinking agent in the primer layer i9s 100/5-100/100.