An impervious breathable film made of a composition that does not include polymers having polyether units and includes one or more polymers, at least one of which is an ethylene copolymer. Said impervious breathable film is moreover made of a comonomer, having the function of an acid or one of the derivatives thereof. In said impervious breathable film, the weight of comonomers, having the function of carboxylic acid or a derivative of said acid, is greater than or equal to 21 wt % in said copolymer. Said impervious film moreover relates to a slip additive. The film has a thickness of 2 to 30 μm. Also, an impervious breathable structure, containing a fibrous material and said film, and moreover relates to a method for manufacturing said structure. Said film and said structure are advantageously usable as an impervious breathable material for, for example, construction siding.