This invention provides a disposable wearing article improved to assure a body waste collecting space having a desired volume may be assured without a problem that a crotch region might expand beyond necessity and thereby to make the article visually favorable. A crotch chassis (12) includes a liquid-impervious sheet (34) having a main region (53) and opposite lateral portions (54) lying outboard of the main region (53) in the transverse direction (X) and provided with leg elastic elements (41, 42) extending in the longitudinal direction. The opposite lateral portions (54) respectively have fold lines (55) extending in the longitudinal direction (Y), outer side zones (54A) lying outboard of the respective fold lines (55) in the transverse direction (X) and inner side zones (54B) lying inboard of the respective fold lines (55) in the transverse direction (X). The outer side zones (54A) of the respective lateral portions (54) are folded inward and fixed to the associated inner side zones (54B) via associated bond zones (57) extending in the longitudinal direction Y to form a pair of elastic lateral portions (40) having folded back regions, respectively.
