Provided is a biodegradable water absorbent having high gel strength and exhibiting an excellent absorption factor and excellent liquid passage rate through a gel. A water absorbent comprising a cross-linked naturally derived polymer and a clay mineral, the water absorbent being characterized in that the cross-linked naturally derived polymer and the clay mineral form particles, the clay mineral is present in the interior of the particles, and the clay mineral content constitutes 10-100 parts by mass (when dry) relative to 100 parts by mass (when dry) of the cross-linked naturally derived polymer. It is possible to produce this water absorbent by preparing a starting material fluid in which the naturally derived polymer is dissolved and the clay mineral is dispersed, adding a cross-linking agent to the starting material fluid, and cross-linking the naturally derived polymer.
