A midsole structure for shoes, including shoes with a vapor-permeable sole, designed for use in sports activities, comprising a monolithic plantar frame made of polymeric material, which comprises a reinforced rim with structural cross-members, which cooperate to delimit opening compartments that pass through the monolithic plantar frame in order to lead onto opposite faces thereof, at least one first vapor-permeable element, which covers at least the opening compartments, which open onto a first one of the faces, with which the first vapor-permeable element is associated, at least one second vapor-permeable element, which covers at least the opening compartments, which open onto the second one of the faces, with which the second vapor-permeable element is associated.