The present invention as a whole is a method for producing water-absorbing polymer particles, comprising (i) at least partially neutralized monoethylenically unsaturated carboxylic acid group-containing monomer (α1) and at least one crosslinking agent. A step of preparing an aqueous monomer solution containing (α3), (ii) a step of adding fine particles of a water-absorbing polymer to the aqueous monomer solution as required, and (iii) a polymerization initiator or two or more components. Adding at least one component of the polymerization initiator system to the monomer aqueous solution； (iv) reducing the oxygen content of the monomer aqueous solution； and (v) charging the monomer aqueous solution into the polymerization reactor； (Vi) a step of polymerizing the monomer in the monomer aqueous solution in the polymerization reactor； and (vii) discharging the polymer gel strand from the polymerization reactor, and if necessary, removing the polymer gel. Pulverizing to obtain polymer gel particles, (viii) drying the polymer gel particles, (ix) pulverizing the dried polymer gel particles to obtain water-absorbing polymer particles, and (x) pulverizing A polymer gel particle obtained in step (vii) in step (viii), comprising: a step of classifying the water-absorbing polymer particles； and (xi) a step of treating the surface of the ground and classified water-absorbing polymer particles. Is placed at a position L0 on the surface of the belt material of the belt dryer and dried by the belt dryer, the belt material being cooled before contact with the polymer gel particles. The present invention also relates to water-absorbing polymer particles obtained by the method according to the present invention, a composite material, a method for producing a composite material, a composite material obtained by the method according to the present invention, a chemical product, and Regarding use.本発明は、全体として、吸水性ポリマー粒子の製造方法であって、（ｉ）少なくとも部分的に中和されたモノエチレン性不飽和カルボン酸基含有モノマー（α１）と、少なくとも１種の架橋剤（α３）と、
