A crosslinked polymer containing a monomer unit derived from a water-soluble ethylenically unsaturated monomer, having an initial swelling force of 8 N or more as measured by a swelling force test performed by a predetermined method, and Disclosed are water-absorbent resin particles in which the ratio of particles having a particle size of more than 250 μm and 850 μm or less is 70% by mass or more and the ratio of particles having a particle size of 250 μm or less is 20% by mass or less based on the total amount of the conductive resin particles. .水溶性エチレン性不飽和単量体に由来する単量体単位を含有する架橋重合体を含み、所定の方法で行われる膨潤力試験で測定される初期膨潤力が８Ｎ以上であり、かつ該吸水性樹脂粒子全量に対し、粒子径が２５０μｍ超８５０μｍ以下である粒子の割合が７０質量％以上であり、２５０μｍ以下である粒子の割合が２０質量％以下である、吸水性樹脂粒子が開示される。
