A DISPOSABLE DIAPER (1, 1X, 1Y, 1Z) HAS A CENTRAL ELASTIC MEMBER (44) FORMED ALONG THE LENGTHWISE DIRECTION L SO THAT THE ABSORBER (40, 40X, 40Y, 40Z) CAN BE CURVED TO BE CONVEX IN THE INWARD DIRECTION, AND A PAIR OF SIDE SLITS (42S) FORMED ALONG THE LENGTHWISE DIRECTION L SO THAT THE ABSORBER (40, 40X, 40Y, 40Z) CAN BE CURVED TO BE CONVEX IN THE OUTWARD DIRECTION. A THICKNESS OF THE ABSORBER (40, 40X, 40Y, 40Z) AT THE CENTRAL PORTION (40C) AND AT THE SIDE EDGE PORTIONS (40S) ARE SMALLER THAN A THICKNESS OF THE ABSORBER (40, 40X, 40Y, 40Z) AT THE MIDDLE PORTIONS (40M). FIG. 6