A patent has been issued for a disposable undergarment comprised of a liquid-pervious top sheet, a liquid-impervious backsheet and a liquid-absorbent panel. The panel is disposed between the topsheet and backsheet. The liquid-absorbent panel is comprised of a body fluid absorbing/holding layer made up of a mixture of fluff pulp, high absorption polymer particles and heat-sealable resin fibers. The body fluid absorbing/holding layer includes an upper and a lower surface and a number of depressions formed in at least one of the upper and the lower surface and a nonwoven fabric layer made up of heat-sealable synthetic resin fibers. The nonwoven fabric layer is placed upon at least one of the upper and lower surfaces of the body fluid absorbing/holding layer, which includes a number of depressions. The absorbing/holding layer and the nonwoven fabric layer are integrally covered with and bonded to a water-pervious sheet. The heat-sealable synthetic resin fibers of the absorbing/holding layer are heat-sealed with the nonwoven fabric layer over contacting surfaces of the absorbing/holding layer and the nonwoven fabric layer and further beat-sealed within the plurality of depressions in the adjacent contacting surface of the body fluid absorbing/holding layer so as to substantially fill the depressions.