FIELD: chemistry.SUBSTANCE: invention relates to superabsorbent polymers. Method of producing water-absorbing polymer involves following steps: (i) mixing: (α1) from 0.1 to 99.999 wt%, preferably from 20 to 98.99 wt%, especially preferably from 30 to 98.95 wt% capable of polymerisation, containing acid groups of ethylenically unsaturated monomers or salts thereof, wherein preferential are mixtures containing at least ethylenically unsaturated monomers with acidic groups, preferably, acrylic acid, (α2) from 0 to 70 wt%, preferably from 1 to 60 wt%, especially preferentially from 1 to 40 wt% capable of polymerisation of ethylenically unsaturated monomers capable of copolymerisation with monomers (α1), (α3) from 0.001 to 10 wt%, preferably from 0.01 to 7 wt%, especially preferably 0.05 to 5 wt% of one or several cross-linking agents, (α4) from 0 to 30 wt%, preferably from 1 to 20 wt%, especially preferably 5-10 wt% of water-soluble polymers, as well as (α5) from 0 to 20 wt%, preferably from 0.01 to 7 wt%, especially preferably 0.05 to 5 wt% one or more auxiliary substances, wherein sum of weight amounts of components (α1)-(α5) is 100 wt%, (ii) radical polymerisation with cross-linking, aim of which is to produce water-insoluble, aqueous raw polymer hydrogel, (iii) drying polymer hydrogel, (iv) milling and sieving polymer hydrogel (v) surface secondary cross-linking of ground and sieved polymer hydrogel and (vi) drying and sorting and packing water-absorbing polymer, wherein before feeding initiator and start radical polymerisation of monomers added to aqueous solution from 0.01 to 5 wt%, preferably, from 0.02 to 2 wt%, especially preferably 0.07 to 1 wt% at least one surfactant, and optionally, from 0.01 to 5 wt%, preferably from 0.02 to 2 wt%, especially preferably 0.07 to 1 wt% blowing agent with particle size ranging from 10 to 900 mcm in terms of water-absorbing polymers, wherein surfactants are capable of copolymerisation with monomers (α1), and a surfactant is se
