A woman's undergarment comprising: a pair of left and right cups; a center cover piece that has a substantially triangular shape whose oblique sides are each sewn to an oblique side sewing portion of one of the left and right cups that extends from a connection point at which the left and right cups are connected at inner ends thereof to a middle point of a lower edge of the one of the left and right cups; a front panel that is provided along, and at a predetermined distance from, a line connecting a bottom side of the center cover piece and lower edge underarm-side portions of the left and right cups each extending from the middle point of the lower edge to an outer end of the lower edge; a stretchable tape that is provided between the front panel and the line connecting the bottom side of the center cover piece and the lower edge underarm-side portions and is sewn to the front panel, the bottom side of the center cover piece, and the lower edge underarm-side portions so as to connect the front panel, the bottom side, and the lower edge underarm-side portions, the stretchable tape having stretchability in both longitudinal and transverse directions thereof; a back panel that is connected to the front panel or hooked belts that are connected to the front panel; shoulder straps that are sewn to the cups and the back panel or the belts; and characterized by left and right upper edge tapes that are each provided along an upper edge of one of the left and right cups and one of the oblique sides of the center cover piece and intersect each other at the front of the undergarment, and that are both stretchable in longitudinal directions thereof, wherein the left and right upper edge tapes are sewn to each other at the intersection. a pair of left and right cups; a center cover piece that has a substantially triangular shape whose oblique sides are each sewn to an oblique side sewing portion of one of the left and right cups that extends from a connection point at which the left and right cups are connected at inner ends thereof to a middle point of a lower edge of the one of the left and right cups; a front panel that is provided along, and at a predetermined distance from, a line connecting a bottom side of the center cover piece and lower edge underarm-side portions of the left and right cups each extending from the middle point of the lower edge to an outer end of the lower edge; a stretchable tape that is provided between the front panel and the line connecting the bottom side of the center cover piece and the lower edge underarm-side portions and is sewn to the front panel, the bottom side of the center cover piece, and the lower edge underarm-side portions so as to connect the front panel, the bottom side, and the lower edge underarm-side portions, the stretchable tape having stretchability in both longitudinal and transverse directions thereof; a back panel that is connected to the front panel or hooked belts that are connected to the front panel; shoulder straps that are sewn to the cups and the back panel or the belts; and characterized by left and right upper edge tapes that are each provided along an upper edge of one of the left and right cups and one of the oblique sides of the center cover piece and intersect each other at the front of the undergarment, and that are both stretchable in longitudinal directions thereof, wherein the left and right upper edge tapes are sewn to each other at the intersection.