According to the invention, there is provided a process for producing
porous polymer particles, which includes: dissolving in an organic
solvent a monomer mixture containing an aromatic vinyl monomer and an
aromatic divinyl monomer as major components together with a
polymerization initiator to obtain a monomer solution; dispersing the
monomer solution in water containing a dispersant and sodium nitrite to
obtain a suspension polymerization dispersion; suspension-polymerizing
the monomers in the suspension polymerization dispersion to yield porous
polymer particles; and separating the porous polymer particles by
filtration through a filter medium, in which the sodium nitrite is
incorporated into the water in an amount in the range of 0.005 to 0.1 mg
per 1 g of the water.