PROBLEM TO BE SOLVED: To suppress the uneven distribution of an absorbent material within a cell while maintaining the advantages of an absorber having the absorbent material movably enclosed within a number of cells.SOLUTION: The absorbent article includes the absorber 56. The absorber includes a first sheet 57 a second sheet 58 having a number of laterally extending pleats which are juxtaposed so as to be fallen in one direction and the absorbent material 59 arranged between the first and second sheets 57, 58. The first sheet 57 is bonded to the first sheet-side bottom at each pleat of the second sheet to form a joint portion, while the first sheet 57 is not bonded to the second sheet 58 each between these joint portions to form a tunnel-like cell 56C, and the granular absorbent material 59 containing at least high absorptive polymer particles is movably enclosed within each cell 56C. The surface close to a top sheet 30 of the absorber has a hard-to-expand portion 90 which is bonded to the top sheet by a linear joint portion 56y extending over a plurality of adjacent cells along a direction crossing the longitudinal middle of the cells and an easy-to-expand portion 91 having no linear joint portion.
