A fiber capable of forming a metal chelate and a process for producing the same are disclosed, wherein the fiber is characterized in that at least one metal chelate-forming compound selected from the group consisting of aminodicarboxylic acids, aminocarboxylic acids, thiocarboxylic acids and phosphoric acid, which are reactive with a glycidyl group, is bonded to a molecule of a natural fiber or regenerated fiber through a crosslinkable compound having a reactive double bond and a glycidyl group in its molecule. There are also disclosed a method of capturing metal ions using the fiber and a metal chelate fiber which can effectively make use of the characteristics of the metals and can be easily discarded or incinerated.