The invention relates to a vapour permeable, water-tight and reflecting foil, comprising at least two layers, a first layer consisting of a vapour permeable, water-tight carrier layer and a second layer consisting of a reflecting layer made of a metal or metal oxide, characterized in that the metal layer is applied without interruption directly onto the carrier layer. The invention further relates to insulating sheets having one or more layers, which comprise the foil according to the invention. The insulating sheet is particularly suited for use in refrigerated containers, in thermal containers, in transport containers, particularly for the shipping, automotive, or aerospace industry, in special-purpose textiles and in footwear.