A diaper (1), which is an embodiment of the present invention, is provided with a front sheet (2), a back sheet (3), and an oblong absorbent body (4) disposed between the front and back sheets (2, 3). The absorbent body (4) has an absorbent core (41). The absorbent core (41) has: vertical grooves (44Y) that extend in the vertical direction (the Y direction) horizontal grooves (44X) that extend in the horizontal direction (the X direction) and block-shaped areas (411) that are positioned at locations partitioned by the vertical grooves (44Y) and the horizontal grooves (44X), and comprise multiple oblong high basis weight areas (43), which have a higher basis weight than the locations of each of the vertical grooves (44Y) and the horizontal grooves (44X). The high basis weight areas (43) of the absorbent core (41), and low basis weight areas (44) comprising locations positioned at each of the vertical grooves (44Y) and the horizontal grooves (44X) are integrally formed. The vertical grooves (44Y) and the horizontal grooves (44X) are formed so as to have the same thickness, or the horizontal grooves are formed more thinly. In a plan view, the width of the horizontal grooves (44X) is formed more widely than the width of the horizontal grooves (44Y).
