There is provided an adhesive for inorganic vapor-deposited film which is characterized in containing a compounded product and/or a reacted product of polyurethane resin or polyester resin having a branch in a molecule with a silane coupling agent. When the said adhesive is directly coated on an inorganic vapor-deposited film and adhered with a heat-sealing resin, a good adhesion is achieved. Also, when a packaging bag prepared by using the above is torn, a good tearing property is achieved.