A chelate compound wherein a chelate-forming moiety is attached to a base compound having an amino group and at least a part of the amino group is in the form of a halide salt. A specific example of the halide salt is hydrochloride. As the base compound, a chitosan having a glucosamine skeleton is preferred. Also, chitosan beads are usable. The chelate compound is produced by reacting the base compound having an amino group with an aldehyde group of an aromatic cyclic compound, aromatic cyclic compound having at least a functional group capable of forming a chelate and the aldehyde group, to form a Schiff base, reducing the Schiff base with a reducing agent and then treating with a hydrohalogenic acid (hydrochloric acid).