A mattress is described, comprising an ergonomic layer made of foam material and a breathable layer made of three-dimensional polymeric material. The ergonomic layer and the breathable layer are mutually coupled. The breathable layer is individually wrapped in a casing made of a three-dimensional breathable fabric. The combination between the breathable layer and the respective casing, which is also manufactured with a three-dimensional breathable type of material, allows to obtain the maximum breathable characteristics for the mattress.