Disclosed is a method for producing water-absorbing resin particles involving a polymerization step in which a suspension is prepared by suspending, in an oil-based solution containing a hydrocarbon dispersion medium and a surfactant with HLB 6 or higher, an aqueous solution containing water and a water-soluble ethylenically unsaturated monomers dissolved in the water, and in which the water-soluble ethylenically unsaturated monomers are polymerized while supplying an inert gas in the suspension. The gas supply ratio represented by the ratio of the volume of inert gas supplied in one minute to the total volume of the aqueous solution and the hydrocarbon dispersion medium is 0.1-3.0.
