A crotch member of a disposable undergarment with a strip shape that is bonded to and bridging between a ventral member and a dorsal member comprising: a ventral bonded portion bonded on the ventral member in an overlapping manner; a dorsal bonded portion bonded on the dorsal member in an overlapping manner; at least one pair of crotch side edge elastic members, wherein the crotch side edge elastic members extend and are bonded along to left and right side edges of the crotch member, and wherein the crotch side edge elastic members are separated from the ventral bonded portion and the dorsal bonded portion; and at least one pair of ventral connection elastic members, wherein the ventral connection elastic members are bonded to the crotch member at a position closer to the center than the positions where the crotch side edge elastic members are bonded to the crotch member, wherein the ventral connection elastic members overlap with the ventral bonded portion at a ventral end portion of the portion where the ventral connection elastic members are bonded to the crotch member, wherein the ventral connection elastic members do not overlap with the dorsal bonded portion at a dorsal end portion of the portion where the ventral connection elastic members are bonded to the crotch member, and wherein the ventral connection elastic members have higher tensile force than the crotch side edge elastic members. a ventral bonded portion bonded on the ventral member in an overlapping manner; a dorsal bonded portion bonded on the dorsal member in an overlapping manner; at least one pair of crotch side edge elastic members, wherein the crotch side edge elastic members extend and are bonded along to left and right side edges of the crotch member, and wherein the crotch side edge elastic members are separated from the ventral bonded portion and the dorsal bonded portion; and wherein the crotch side edge elastic members extend and are bonded along to left and right side edges of the crotch member, and wherein the crotch side edge elastic members are separated from the ventral bonded portion and the dorsal bonded portion; and at least one pair of ventral connection elastic members, wherein the ventral connection elastic members are bonded to the crotch member at a position closer to the center than the positions where the crotch side edge elastic members are bonded to the crotch member, wherein the ventral connection elastic members overlap with the ventral bonded portion at a ventral end portion of the portion where the ventral connection elastic members are bonded to the crotch member, wherein the ventral connection elastic members do not overlap with the dorsal bonded portion at a dorsal end portion of the portion where the ventral connection elastic members are bonded to the crotch member, and wherein the ventral connection elastic members have higher tensile force than the crotch side edge elastic members. wherein the ventral connection elastic members are bonded to the crotch member at a position closer to the center than the positions where the crotch side edge elastic members are bonded to the crotch member, wherein the ventral connection elastic members overlap with the ventral bonded portion at a ventral end portion of the portion where the ventral connection elastic members are bonded to the crotch member, wherein the ventral connection elastic members do not overlap with the dorsal bonded portion at a dorsal end portion of the portion where the ventral connection elastic members are bonded to the crotch member, and wherein the ventral connection elastic members have higher tensile force than the crotch side edge elastic members.