The present invention aims to provide a pants type disposable diaper free from noticeable gathers formed on the innermost side of the crotch region.In the crotch region of the pants type disposable diaper, the bodily fluid-absorbent core 26 is sandwiched between the liquid-permeable inner sheet 23 and the liquid-impermeable outer sheet 24. Further inside the inner sheet 23, the innermost sheet 21 is provided and this innermost sheet 21 prevents the inner sheet 23 from coming in contact with the wearers skin. The innermost sheet 21 is joined, in the regions extending in the vicinity of the ends thereof opposite in the front-back direction A, to at least one of the inner sheet 23 and the outer sheet 24. The innermost sheet 21 includes, in its region defined on the transverse center line P of the diaper 1, the tuck 36 extending downward toward the inner sheet 23.
