A liquid vaporizer includes a stack of coaxially aligned, thermally conductive, thin, flat disks having different diameters. The larger diameter disks each include at least one aperture and preferably a plurality of closely spaced apertures radially located a predetermined distance from the center of the disk. The vaporizer further includes means for establishing a liquid film on at least a portion of the surfaces of the larger diameter disks and for accelerating the vaporization of the liquid thereon by passing a gas through the apertures of the larger diameter disks over the liquid film on the portion of the surfaces of the larger diameter disks.