A trunks-type disposable diaper comprising: an outer member having a waist opening and a pair of leg openings and extending from a front waist opening edge to a back waist opening edge; an inner member provided at least in a crotch portion of the outer member and including an absorber; and side seal portions that bond both sides on a front side and both sides on a back side of the outer member, in which the absorber has a narrower portion which is narrower than both front and back sides in an intermediate portion in a front-back direction, the crotch portion of the outer member has a pair of inner thigh contact portions which respectively extend towards one side and the other side in a width direction from a circumscribed rectangle of the absorber, and portions along edges of the leg openings including the inner thigh contact portions forms a pair of cylindrical leg portions surrounding root sides of the thighs, the front side of the outer member has one elongated front around-leg elastic member or a plurality of elongated front around-leg elastic members not crossing each other, the elastic member is attached in a pattern of extending from one of the side seal portions toward the center in the width direction along the edge of the leg opening, crossing the center in the width direction, extending toward the other leg opening, extending to the other side seal portion along the edge of the other leg opening, the back side of the outer member has one elongated back around-leg elastic member or a plurality of elongated back around-leg elastic members not crossing each other, the elastic member is attached in a pattern of extending from one of the side seal portions toward the center in the width direction along the edge of the leg opening, crossing the center in the width direction, extending toward the other leg opening, and extending to the other side seal portion along the edge of the other leg opening, and the front around-leg elastic member and the back around-leg elastic member are attached in a pattern in which at least one front around-leg elastic member and at least one back around-leg elastic member cross each other on both sides in the width direction of an intermediate region that is a region between the edge of one leg opening and the edge of the other leg opening, wherein a crossing position of the front around-leg elastic member and the back around-leg elastic member, positioned closest to the edge side of the leg opening is the same in the width direction position as a side edge of the narrowest part of the narrower portion or located on the further center side in the width direction, and the crotch portion does not have elastic members other than the front around-leg elastic member and the back around-leg elastic member. an outer member having a waist opening and a pair of leg openings and extending from a front waist opening edge to a back waist opening edge; an inner member provided at least in a crotch portion of the outer member and including an absorber; and side seal portions that bond both sides on a front side and both sides on a back side of the outer member, in which the absorber has a narrower portion which is narrower than both front and back sides in an intermediate portion in a front-back direction, the crotch portion of the outer member has a pair of inner thigh contact portions which respectively extend towards one side and the other side in a width direction from a circumscribed rectangle of the absorber, and portions along edges of the leg openings including the inner thigh contact portions forms a pair of cylindrical leg portions surrounding root sides of the thighs, the front side of the outer member has one elongated front around-leg elastic member or a plurality of elongated front around-leg elastic members not crossing each other, the elastic member is attached in a pattern of extending from one of the side seal portions toward the center in the width direction along the edge of the leg opening, crossing the center in the width direction, extending toward the other leg opening, extending to the other side seal portion along the edge of the other leg opening, the back side of the outer member has one elongated back around-leg elastic member or a plurality of elongated back around-leg elastic members not crossing each other, the elastic member is attached in a pattern of extending from one of the side seal portions toward the center in the width direction along the edge of the leg opening, crossing the center in the width direction, extending toward the other leg opening, and extending to the other side seal portion along the edge of the other leg opening, and the front around-leg elastic member and the back around-leg elastic member are attached in a pattern in which at least one front around-leg elastic member and at least one back around-leg elastic member cross each other on both sides in the width direction of an intermediate region that is a region between the edge of one leg opening and the edge of the other leg opening, wherein a crossing position of the front around-leg elastic member and the back around-leg elastic member, positioned closest to the edge side of the leg opening is the same in the width direction position as a side edge of the narrowest part of the narrower portion or located on the further center side in the width direction, and the crotch portion does not have elastic members other than the front around-leg elastic member and the back around-leg elastic member.