This diaper (1A) is provided with an absorbent main unit (2) having an absorber (23), and elastic side panels (3) attached to both side portions (2S) of the absorbent main unit (2). The absorbent main unit (2) has side sheets (24) disposed on both side portions (2S) thereof. The side panels (3) are formed so as to fix elastic members (33), which are in a state of being elongated in the X-direction, between two side panel sheets (31 and 32) by way of a main unit-side adhesive layer (35) and an outer-side adhesive layer (36). On the side panels (3), in a natural state, by way of contractive force of the elastic members (33), between the main unit-side adhesive layer (35) and the outer-side adhesive layer (36), a gathering area (GT) is formed, comprising hollow gathers in which the respective elastic member (33) is not fixed by the side panel sheets (31 and 32). In this diaper (1A), outer-side edge portions (2S1) along the Y-direction of the absorbent main unit (2) are upon the gathering areas (GT) of the side panels (3).本發明之尿布(1A)包括包含吸收體(23)之吸收性本體(2)及安裝於吸收性本體(2)之兩側部(2S)之伸縮性之側片(3)。吸收性本體(2)包含配置於兩側部(2S)之側部片材(24)。側片(3)係將於(X)方向上伸長狀態之彈性構件(33)藉由本體側接著劑層(35)及前端側接著劑層(36)固定於兩片側片片材(31)、(32)之間而形成。於側片(3)，在自然狀態下，藉由彈性構件(33)之收縮力，於本體側接著劑層(35)與前端側接著劑層(36)之間，形成包含彈性構件(33)未固定於側片片材(31)、(32)之中空皺襞之褶皺區域(GT)。本發明之尿布(1A)中，吸收性本體(2)之沿(Y)方向之外方側緣部(2S1)位於側片(3)之褶皺區域(GT)上。
