A method for manufacturing a paper barrier base material, comprising: a step of applying a water vapor barrier layer coating liquid that contains at least a water vapor barrier resin and a pigment onto a paper base material by a curtain coating method to form a water vapor barrier layer, wherein the water vapor barrier resin is selected from the group consisting of a styrenebutadiene, styrene-acrylic, ethylene-vinyl acetate, paraffin, butadiene-methyl methacrylate, or vinyl acetate-butyl acrylate copolymer, a maleic anhydride copolymer, or an acrylic acid-methyl methacrylate copolymer; or a paraffin -blended synthetic adhesive or a mixture of two or more thereof; and a step of applying a gas barrier layer coating liquid that contains at least one polymer selected from water-soluble polymers and water-dispersible polymers onto the water vapor barrier layer by a curtain coating method without a drying step interposed between the two steps to form a gas barrier layer, wherein the water-soluble polymer is selected from the group consisting of polyvinyl alcohols, proteins, starches, cellulose derivatives, polyvinylpyrrolidone, and sodium alginate, or a mixture of two or more thereof; wherein the water-dispersible polymer is selected from the group consisting of polyvinylidene chloride, ethylene vinyl acetate resins, and modified polyolefin resins, or a mixture of two or more thereof; and wherein one or both of the water-soluble polymer and the water-dispersible polymer may be used; wherein the gas barrier layer coating liquid has a B-type viscosity higher than a B-type viscosity of the water vapor barrier layer coating liquid, and wherein the difference between the B-type viscosity of the gas barrier layer coating liquid and the B-type viscosity of the water vapor barrier layer coating liquid is 10 mPa·s or more and 220 mPa·s or less, wherein the B-type viscosity is measured with a Brookfield viscometer (BII viscometer, manufactured by Tokyo Keiki Inc.) at a temperature of 25°C using a No. 3 rotor at a rotation speed of 60 rpm; and wherein the water vapor barrier layer coating liquid has a solid content concentration of 25% by weight or more and 45% by weight or less, and the gas barrier layer coating liquid has a solid content concentration of 15% by weight or more and 35% by weight or less. a step of applying a water vapor barrier layer coating liquid that contains at least a water vapor barrier resin and a pigment onto a paper base material by a curtain coating method to form a water vapor barrier layer, wherein the water vapor barrier resin is selected from the group consisting of a styrenebutadiene, styrene-acrylic, ethylene-vinyl acetate, paraffin, butadiene-methyl methacrylate, or vinyl acetate-butyl acrylate copolymer, a maleic anhydride copolymer, or an acrylic acid-methyl methacrylate copolymer; or a paraffin -blended synthetic adhesive or a mixture of two or more thereof; and a step of applying a gas barrier layer coating liquid that contains at least one polymer selected from water-soluble polymers and water-dispersible polymers onto the water vapor barrier layer by a curtain coating method without a drying step interposed between the two steps to form a gas barrier layer, wherein the water-soluble polymer is selected from the group consisting of polyvinyl alcohols, proteins, starches, cellulose derivatives, polyvinylpyrrolidone, and sodium alginate, or a mixture of two or more thereof; wherein the water-dispersible polymer is selected from the group consisting of polyvinylidene chloride, ethylene vinyl acetate resins, and modified polyolefin resins, or a mixture of two or more thereof; and wherein one or both of the water-soluble polymer and the water-dispersible polymer may be used; wherein the gas barrier layer coating liquid has a B-type viscosity higher than a B-type viscosity of the water vapor barrier layer coating liquid, and wherein the difference between the B-type viscosity of the gas barrier layer coating liquid and the B-type viscosity of the water vapor barrier layer coating liquid is 10 mPa·s or more and 220 mPa·s or less, wherein the B-type viscosity is measured with a Brookfield viscometer (BII viscometer, manufactured by Tokyo Keiki Inc.) at a temperature of 25°C using a No. 3 rotor at a rotation speed of 60 rpm; and wherein the water vapor barrier layer coating liquid has a solid content concentration of 25% by weight or more and 45% by weight or less, and the gas barrier layer coating liquid has a solid content concentration of 15% by weight or more and 35% by weight or less.