A transparent, gas-permeable and waterproof film, particularly for applications in the medical field is disclosed. The film includes a polyolefin base, to which is added a monomeric plasticiser with a percentage by mass of between 10% and 50% and preferably also molecular sieves with a percentage by mass of less than or equal to 20%, this addition enables in particular the gas permeability of the film to be increased, said film thus having a high gas permeability, as well as low water permeability and high transparency, together with various mechanical characteristics and properties so that it is particularly well suited to many applications, in particular in the medical sector and in particular for application to an identification card used in the medical diagnosis.