A DISPOSABLE PANT-TYPE DIAPER (1) ACCORDING TO THE PRESENT INVENTION INCLUDES A FRONT PORTION (4), A BACK PORTION (5), AND A CROTCH PORTION (6) WHICH IS POSITIONED BETWEEN THE FRONT AND BACK PORTIONS (4, 5), IN WHICH A WAIST OPENING (8) AND A PAIR OF LEG OPENINGS (9) ARE FORMED BY JOINING BOTH LONGITUDINAL SIDE-EDGE PORTIONS OF THE FRONT AND BACK PORTIONS WHICH FACE EACH OTHER, AND STRETCHABLE ELASTIC MEMBERS (10) AND (11) ARE DISPOSED ALONG AT LEAST A PART OF EACH OPENING, WHEREIN A CUTOUT PORTION (12) IS FORMED IN AT LEAST A PORTION OF THE SIDE-EDGE PORTION OF AT LEAST ONE OF THE FRONT AND BACK PORTIONS, AND THE FRONT AND BACK PORTIONS ASSUME A NON-JOINING STATE AT THE PORTION WHERE THE CUTOUT PORTION IS FORMED
