PROBLEM TO BE SOLVED: To provide a single opening type underpants type diaper, which can easily fit to a girth of a wearer.SOLUTION: There is provided a single opening type underpants type diaper (1) comprising: a front girth part (30) a rear girth part (20) and an absorbent body (10). The rear girth part (20) has a rubber thread (23) which is along a lateral direction, and an end part on one side of the rear girth part (20) and an end part on one side of the front girth part (30) are jointed by a first junction (1b). An end part on the other side of the rear girth part (20) is jointed to an engagement member (40) having an engagement part (41) which can engage to the front girth part (30) in wearing, by a second junction (2b). In the second junction (2b), the end part on the other side of the rear girth part (20) and the engagement member (40) are projected to a non-skin side and skin side surfaces thereof are jointed. A short part (402) of engagement member (40) is provided on the other side relative to the second junction (2b), and a long part (403) thereof is provided on the other side relative to the short part (402).SELECTED DRAWING: Figure 5COPYRIGHT: (C)2018,JPO&INPIT【課題】片開きパンツ型のおむつにおいて、着用者の胴回りにフィットさせやすくする。【解決手段】前胴回り部(30)と、後胴回り部(20)と、吸収性本体(10)と、を備えた片開きパンツ型のおむつ(1)であって、後胴回り部(20)は、横方向に沿った糸ゴム(23)を有しており、後胴回り部(20)の一方側の端部と、前胴回り部(30)の一方側の端部とは、第1接合部(1b)によって接合されており、後胴回り部(20)の他方側の端部は、着用時に前胴回り部(30)に係止可能な係止部(41)を有する係止部材(40)と第2接合部(2b)によって接合されており、第2接合部(2b)では、後胴回り部(20)の他方側の端部と係止部材(40)とが、肌側面同士が接合されて非肌側に突出しており、係止部材(40)は、短部(402)を第2接合部(2b)よりも他方側に有し、長部(403)を短部(402)よりも他方側に有している。【選択図】図5
