To provide: a process in which a coarse gel itself is made not to form in the case of applying the
aqueous solution polymerization; and a process in which the
polymerization is mildly controlled and the production is stably carried out in the case of applying the reversed-phase
suspension polymerization or static
polymerization, in a production of a water-absorbent resin. In a production process for a water-absorbent resin, which comprises a polymerization step that includes the steps of carrying out polymerization, involving crosslinking, of an
aqueous solution of a water-soluble
unsaturated monomer including
acrylic acid(salt);and at the same time carrying out fine division of the
resultant hydrogel, or in a production process for a water-absorbent resin, which comprises the steps of carrying out polymerization, involving crosslinking, of an
aqueous solution of a water-soluble
unsaturated monomer including
acrylic acid(salt);and carrying out fine division of the
resultant hydrogel, or in a production process for a water-absorbent resin, which comprises a polymerization step that includes the steps of carrying out polymerization, involving crosslinking, of an aqueous solution of a water-soluble
unsaturated monomer including
acrylic acid(salt); and at the same time obtaining a finely divided hydrogel, the water-soluble unsaturated
monomer is adjusted in order to contain
furfural in an amount of 11 to 1,000 weight ppm (relative to the
monomer).