A ventilation sole for footwear, in which an air inlet-outlet is formed in a side of the ventilation sole, vents are formed in an upper portion of the ventilation sole, the vents communicating with the air inlet-outlet, and a device for opening and closing an air inlet-outlet, which is coupled with the air inlet-outlet, supplies ambient air into the footwear, wherein the device for opening and closing an air inlet-outlet comprises: a main cap, wherein front and rear portions of the main cap have an open structure to form a flow passage; a button cap inserted into the main cap, wherein the button cap is coupled such that it is exposed through the air inlet-outlet, and is locked or unlocked; wherein the button cap inserted into and coupled with the main cap, wherein a pressure section is formed in a central portion of the button cap, ambient air inlet-outlet holes are formed around the pressure section, and a head is exposed to the air inlet-outlet; wherein the button cap is movable between a locked position and an unlocked position by rotation and an elastic stopper inserted into the main cap, wherein the elastic stopper elastically advances and retreats in response to a locking or unlocking action of the button cap, thereby opening or closing the flow passage formed in the main cap, wherein the elastic stopper has an elastic section butted against the pressure section of the button cap, air inlet-outlet passages (350, 360), a spring, one end of the spring being supported on the other side of the elastic stopper, such that the elastic stopper elastically advances or retreats in response to a locking or unlocking action of the button cap; an elastic stopper holder disposed inside the main cap, wherein the elastic stopper holder contains the elastic stopper therein, and is sealably coupled with the elastic stopper via a sealing member, such that a seal between the elastic stopper and the elastic stopper holder is released when the button cap is locked; and a spring cover inserted into the main cap, wherein the spring cover is closely coupled with the elastic stopper holder, supports the other end of the spring of the elastic stopper, and has an inner air inlet-outlet in a central portion thereof. a main cap, wherein front and rear portions of the main cap have an open structure to form a flow passage; a button cap inserted into the main cap, wherein the button cap is coupled such that it is exposed through the air inlet-outlet, and is locked or unlocked; wherein the button cap inserted into and coupled with the main cap, wherein a pressure section is formed in a central portion of the button cap, ambient air inlet-outlet holes are formed around the pressure section, and a head is exposed to the air inlet-outlet; wherein the button cap is movable between a locked position and an unlocked position by rotation and an elastic stopper inserted into the main cap, wherein the elastic stopper elastically advances and retreats in response to a locking or unlocking action of the button cap, thereby opening or closing the flow passage formed in the main cap, wherein the elastic stopper has an elastic section butted against the pressure section of the button cap, air inlet-outlet passages (350, 360), a spring, one end of the spring being supported on the other side of the elastic stopper, such that the elastic stopper elastically advances or retreats in response to a locking or unlocking action of the button cap; an elastic stopper holder disposed inside the main cap, wherein the elastic stopper holder contains the elastic stopper therein, and is sealably coupled with the elastic stopper via a sealing member, such that a seal between the elastic stopper and the elastic stopper holder is released when the button cap is locked; and a spring cover inserted into the main cap, wherein the spring cover is closely coupled with the elastic stopper holder, supports the other end of the spring of the elastic stopper, and has an inner air inlet-outlet in a central portion thereof.