Provided are an absorbent and an absorptive article containing the absorbent which has excellent water absorbability and leakage prevention ability, and has an intent to achieve reductions in the weight and thickness of an absorptive article. The absorbent comprises a polysaccharide that causes a gelation reaction in the presence of a polyvalent metal ion and a source of the polyvalent ion, in which the polyvalent ion is supplied simultaneously with or after dissolution and swelling of the polysaccharide. The absorptive article containing the absorbent can achieve excellent water absorbability and leakage prevention ability and thus reductions in the weight and thickness as the absorptive article.
