A pants-type disposable wearing article wherein each of the side seams has a desired joint strength and the joint should not unintentionally be released particularly in the bottom segment during use of the wearing article. Respective side seams 26 are formed of a plurality of sealing spots 29 arranged in a direction along a longitudinal axis P. Each of the side seams 26 includes a top segment 71 lying adjacent to a peripheral edge 27a of each waist-opening and a bottom segment 72 lying adjacent to a crotch region 15, wherein each of the sealing spots 29 has a substantially uniform area and a dimension of the bottom segment 72 in a direction along a transverse axis Q is larger than a dimension of the top segment 71 in the direction along the transverse axis Q.