Disclosed herein is method for producing an iron dinuclear complex having two iron atoms bonded to each other via one oxygen atom and a ligand structure containing a Schiff base, a method which can produce an ester compound in high yield by the transesterification of an alcohol compound with a carboxylate ester even in the case where the raw material alcohol has a tertiary hydroxyl group which is usually difficult to esterify by transesterification, and a method which can produce a wholly esterified compound by transesterification catalyzed by an iron complex.