The invention relates to a self-ventilated, ergonomic footwear item and elastomeric sole. According to the invention, both sides of the sole comprise a plurality of longitudinal grooves, in the area corresponding to the sole of the foot, which are essentially parallel to the edge of the sole closest thereto and which have a depth equal to half of the height of the sole. Moreover, the grooves are disposed in an alternating manner in relation to one another on either side of the sole in the form of a bellows-type structure. The upper comprises a perforated elastic laminar body which is disposed beneath the insole in the area corresponding to the sole and the foot and which, together with the sole, forms a chamber having a volume that varies upon walking. In addition, three thick bands are solidly connected to the body and the upper in order to stiffen said elastic laminar body, namely: one longitudinal band and two transverse end bands. In this way the footwear item and the sole adapt perfectly to the anatomy of the foot, enabling same to be automatically ventilated upon walking.