A disposable wearing article having a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, comprising a side facing the wearer's skin and a side facing away from the wearer's skin, a front waist region, a rear waist region and a crotch region extending between the front and rear waist regions, wherein: the front and rear waist regions (13, 14) are defined by an annular waist panel, the waist panel includes a front waist panel defining the front waist region and a rear waist panel defining the rear waist region, and a crotch member is attached to the waist panel, the crotch member has a front end attached to the outer surface of the front waist panel, a rear end attached to the outer surface of the rear waist panel, an intermediate zone extending in the longitudinal direction between the front and rear ends (35, 36), a crotch topsheet formed of a plastic film, a crotch backsheet formed of a breathable and hydrophobic nonwoven fabric and a liquid-absorbent structure attached to the side of the crotch topsheet facing the wearer's skin, lateral portions of the crotch topsheet and the crotch backsheet are bonded to each other with hot melt adhesives applied to at least one of these sheets (38, 39) and folded inward to define a pair of elasticized lateral portions extending in the longitudinal direction on the inner surface of the liquid-absorbent structure, each of the elasticized lateral portions has an inner side edge defined by the side edges of the crotch top- and back sheets (38, 39) bonded together, front and rear ends (44, 45) and an outer side edge defined by fold lines along which the elasticized lateral portions are folded inward, the front and rear ends (44, 45) of the elasticized lateral portions are secured to the front and rear ends (31, 32) of the crotch member by bonding means, the elasticized lateral portions are respectively provided with a plurality of strand- or string-liise first leg elastic elements and a plurality of strand- or string-like second leg elastic elements and thereby the elasticized lateral portions are elasticized at least in the longitudinal direction, the first and second leg elastic elements (50, 51) are sandwiched between the crotch topsheet and the crotch backsheet and secured thereto under tension in the longitudinal direction with hot melt adhesives, the first leg elastic elements include three elastic elements rectilinearly extending along the inner side edge of the elasticized lateral portions in the longitudinal direction, the second leg elastic elements extend in the longitudinal direction outboard of the first leg elastic elements as viewed in the transverse direction, each of the second leg elastic elements has a shape concavely curved in a longitudinally middle zone of the crotch region and in the vicinity thereof, and elasticized regions defined by the first leg elastic elements have tensile stress higher than that of elasticized regions defined by the second leg elastic elements. the front and rear waist regions (13, 14) are defined by an annular waist panel, the waist panel includes a front waist panel defining the front waist region and a rear waist panel defining the rear waist region, and a crotch member is attached to the waist panel, the crotch member has a front end attached to the outer surface of the front waist panel, a rear end attached to the outer surface of the rear waist panel, an intermediate zone extending in the longitudinal direction between the front and rear ends (35, 36), a crotch topsheet formed of a plastic film, a crotch backsheet formed of a breathable and hydrophobic nonwoven fabric and a liquid-absorbent structure attached to the side of the crotch topsheet facing the wearer's skin, lateral portions of the crotch topsheet and the crotch backsheet are bonded to each other with hot melt adhesives applied to at least one of these sheets (38, 39) and folded inward to define a pair of elasticized lateral portions extending in the longitudinal direction on the inner surface of the liquid-absorbent structure, each of the elasticized lateral portions has an inner side edge defined by the side edges of the crotch top- and back sheets (38, 39) bonded together, front and rear ends (44, 45) and an outer side edge defined by fold lines along which the elasticized lateral portions are folded inward, the front and rear ends (44, 45) of the elasticized lateral portions are secured to the front and rear ends (31, 32) of the crotch member by bonding means, the elasticized lateral portions are respectively provided with a plurality of strand- or string-liise first leg elastic elements and a plurality of strand- or string-like second leg elastic elements and thereby the elasticized lateral portions are elasticized at least in the longitudinal direction, the first and second leg elastic elements (50, 51) are sandwiched between the crotch topsheet and the crotch backsheet and secured thereto under tension in the longitudinal direction with hot melt adhesives, the first leg elastic elements include three elastic elements rectilinearly extending along the inner side edge of the elasticized lateral portions in the longitudinal direction, the second leg elastic elements extend in the longitudinal direction outboard of the first leg elastic elements as viewed in the transverse direction, each of the second leg elastic elements has a shape concavely curved in a longitudinally middle zone of the crotch region and in the vicinity thereof, and elasticized regions defined by the first leg elastic elements have tensile stress higher than that of elasticized regions defined by the second leg elastic elements.