Abstract: A breathable sole structure has a lower face (2) which in practice forms the tread, and an upper face (3) which in practice faces the inside of the item of footwear, the breathable sole structure (1) having at least one ventilation duct (4) extending from an inlet section (5) made in the upper face (3) to an outlet section (6) made in the lower face (2). The ventilation duct (4) comprises at least one main stretch (7) which is substantially parallel with a longitudinal direction of extension of the sole structure (1) and has a first end (8) and a second end (9) in communication with the outlet section (6). A dome-shaped portion (10) which is elastically deformable is made on the upper face (3) and inside it forms a chamber (11) connected to the first end (8) of the main stretch (7). The dome-shaped portion also has an opening which forms the ventilation duct (4) inlet section (5).