A millimeter-wave antenna for 5G applications is provided which includes an upper outer layer with a plurality of first radiating elements arranged spaced apart from each other on a first dielectric sublayer, a first inner layer arranged below the upper outer layer and having a plurality of through slots for conveying, towards the first radiating elements feeding signals to be radiated, a second inner layer arranged below and adjacent to the first inner layer having a dielectric sublayer on which there is arranged a plurality of conductive lines for conducting the feeding signals to be radiated towards the first radiating elements, a further inner layer arranged below and adjacent to the second inner layer, and a plurality of first through openings each formed on the further inner layer in a position corresponding to the position of an associated through slot.