The present invention relates to a laminate comprising at least three layers, paper/polyethylene/polyethylene terephthalate, wherein the polyethylene terephthalate is directly coated on the polyethylene surface, with no adhesive layer or the like being interposed, and the polyethylene terephthalate layer has heat sealability; and a method for producing a laminate having polyethylene coated on at least one surface of a paper substrate, the method involving extrusion laminating polyethylene terephthalate onto a surface of the polyethylene, wherein an air gap expressed as the distance from a lip opening of a die to the polyethylene surface is 25 cm or less.