Underpants-type disposable diaper

1. An underpants-type disposable diaper, in which a front side outer member disposed in a front body and a back side outer member disposed in a back body are separately provided, the front side outer member and the back side outer member are spaced apart in the front-back direction at the middle in the front-back direction,

an inner member having a liquid pervious top sheet, a liquid impervious sheet, and an absorber interposed therebetween extends in the front-back direction from the front side outer member to the back side outer member, the inner member is joined to each of the front side outer member and the back side outer member,

a cover nonwoven fabric covering a back surface of the inner member is provided from between the front side outer member and the inner member to between the back side outer member and the inner member,

both sides of the front side outer member and both sides of the back side outer member are joined to each other, a waist opening and a pair of right and left leg openings are included, and

elastic members are incorporated in the front side outer member and the back side outer member,

wherein the cover nonwoven fabric is provided with a plurality of holes penetrating a front surface and a back surface of the cover nonwoven fabric from between the front side outer member and the inner member to between the back side outer member and the inner member at intervals,

wherein the front side outer member and the back side outer member have, at least at portions overlapping with the cover nonwoven fabric and not having any elastic member, a total luminous transmittance of 50% or more,

wherein the underpants-type disposable diaper comprises side gathers extending from both sides of the inner member so as to be in contact with the legs of a wearer and each of the side gathers having a base end on a side portion on a back surface side of the liquid impervious sheet in the inner member, and a gather nonwoven fabric forming an outer surface at least from the base end to a tip end,

wherein the cover nonwoven fabric extends at least from between a base portion of one of the side gathers and the liquid impervious sheet to between a base portion of the other side gather and the liquid impervious sheet, and

wherein the gather nonwoven fabric has a total luminous transmittance of 60 to 90%.

2. The underpants-type disposable diaper according to claim 1 , comprising inner decorative printing, which is visible on outer surfaces of the front side outer member and the back side outer member, on the liquid impervious sheet at least in a region thereof, which overlaps the front side outer member and the back side outer member,

wherein the inner decorative printing overlaps with the holes at least in a part of the cover nonwoven fabric.

3. The underpants-type disposable diaper according to claim 2 , wherein at least either of the front side outer member and the back side outer member is joined to the inner member, at regions overlapping with both end portions in the width direction of the inner member, and is not joined or is intermittently and peelably joined to the inner member, at a part on a crotch side or a whole part in the front-back direction of a region between the regions overlapping with the both end portions in the width direction of the inner member.

4. The underpants-type disposable diaper according to claim 2 , wherein at least either of a region where the front side outer member and the cover nonwoven fabric overlap with each other and a region where the back side outer member and the cover nonwoven fabric overlap with each other includes, on an outer side of the cover nonwoven fabric, a portion provided with an outer decorative sheet having outer decorative printing and a portion not having the outer decorative sheet.

5. The underpants-type disposable diaper according to claim 4 , wherein the inner decorative printing is a continuous decorative printing comprising a plurality of elements regularly repeating in the front-back direction and the width direction, and the outer decorative printing is an intermittent decorative printing arranged only in one or both of front and back sides of a product.

6. The underpants-type disposable diaper according to claim 5 , wherein at least either of the front side outer member and the back side outer member is joined to the inner member, at regions overlapping with both end portions in the width direction of the inner member, and is not joined or is intermittently and peelably joined to the inner member, at a part on a crotch side or a whole part in the front-back direction of a region between the regions overlapping with the both end portions in the width direction of the inner member.

7. The underpants-type disposable diaper according to claim 4 , wherein at least either of the front side outer member and the back side outer member is joined to the inner member, at regions overlapping with both end portions in the width direction of the inner member, and is not joined or is intermittently and peelably joined to the inner member, at a part on a crotch side or a whole part in the front-back direction of a region between the regions overlapping with the both end portions in the width direction of the inner member.

8. The underpants-type disposable diaper according to claim 1 , wherein at least either of the front side outer member and the back side outermember is joined to the inner member, at regions overlapping with both end portions in the width direction of the inner member, and is not joined or is intermittently and peelably joined to the inner member, at a part on a crotch side or a whole part in the front-back direction of a region between the regions overlapping with the both end portions in the width direction of the inner member.