A disposable undergarment has been issued a patent. The undergarment includes a substantially liquid-impervious base sheet with an inner surface; a liquid-absorbent panel attached to the inner surface of the base sheet; a front waist region; a rear waist region and a crotch region extending between the front waist region and the rear waist region. The crotch region has transversely opposite sides that include transversely opposite side edge portions configured to define leg-holes curving transversely inward to make arcs. The base sheet is folded back at least once onto itself along the transversely opposite side edge portions configured to define the leg-holes without any intermediate element positioned between portions of the base sheet that are folded back onto itself. The base sheet has a basis weight in the transversely opposite side edge portions that is higher than a basis weight in a remaining area of the base sheet. The base sheet has a tensile stress that is higher in the transversely opposite side edge portions than a tensile stress in the remaining area of the base sheet. The disposable undergarment also includes a substantially liquid-impervious cover sheet placed on the liquid-absorbent panel and on the sheet. The cover sheet has an elastic stretchability and at least one opening that is elongated in an inner surface of the base sheet so as to cover an entire area of the liquid-absorbent panel and the base longitudinal direction with a peripheral portion thereof joined to a peripheral portion of the base sheet. The cover sheet is folded back at least once onto itself and joined together along the transversely opposite side edge portions configured to define the leg holes so that a basis weight of the cover sheet is higher in the transversely opposite side edge portions configured to define the leg-holes than a basis weight in a remaining area of the cover sheet. A tensile stress of the cover sheet is higher in the transversely opposite side edge portions configured to define the leg-holes than a tensile stress in the remaining area of the cover sheet.