A sole for shoe of elastic material is provided with valves placed at its sides for discharging inner air, each said valve consisting of a through channel (4) formed in the thickness of the sole and not involving the tread of the sole, which channel (4) connects the interior of the shoe to the outside and is closed by a perforated diaphragm or membrane (2) of elastic material provided with a convexity directed to the outside and forming a check valve. Advantageously, said valves are made in one piece of elastic material with the sole during the same moulding step, the membrane being provided with microholes in a later step.