PURPOSE: To adsorb desired metals with high efficiency by preparing a micro- porous ion selective exchange resin by reaction of a specific metal complex and a monomer or oligomer crosslinking agent having ≥2 polymerizable carbon- carbon multiple bonds.

CONSTITUTION: The micro-porous ion selective exchange resin is produced by reacting the metal complex expressed by formula I (M denotes zinp, cadmium, lead, nickel, cobalt, copper, silver and other noble metals; L denotes a polymerizable ligand; B denotes a nonpolymerizable ligand; X denotes a nonpolymerizable anion; a denotes an integer from 1 to 6; b denotes an integer from 1 to 8; c denotes an integer from 0 to 4; d denotes an integer from 0 to 6) and the monomer or oligomer crosslinking agent having at least the two polymerizable carbon-carbon multiple bonds. The resulted ion exchange resin is so pulverized that a desired particulate size is obtd.