To provide an absorbent article which is hardly flattened against pressure and is reduced in fluid back flow.

The absorbent article 10 is equipped with a member configured including fiber containing a polysiloxane crosslinking substance. The member, for instance, may be a liquid retainable absorptive body 13, a water-permeable surface sheet 11, or a second sheet 14 placed between a surface sheet 11 and the absorptive body 13. The fiber contains alkoxysilane (A), organic acid (B), and water (C) and the polysiloxane crosslinking substance is included inside by treating the material fiber by fiber treating liquid with the water (C) more than three times mole as much as the alkoxilane silane (A) and a pH of 2-5.