A liquid is vaporized by a device having at least one porous substrate exposed to a certain ambient pressure, means for supplying the substrate with liquid in order for it to be loaded with liquid starting from an upstream portion of the substrate, and at least one energy source for heating the substrate so that at least some of the liquid is vaporized. According to the invention, the means for supplying the substrate with liquid may include means for pressurizing the liquid to a pressure greater than ambient pressure, thereby creating a flow-rate greater than the flow-rate induced by capillarity and vaporization of the liquid alone when the substrate is held in a horizontal position. The invention may be applied to the production of water-vaporization equipment, particularly with electrical or gaseous energy supply.