An iridium complex is disclosed, which has a structure represented by the following formula (I): ##STR00001## wherein each of Z.sub.1 and Z.sub.3 represents an atomic group for forming a nitrogen-containing heteroaryl group or a nitrogen-containing heterocycloalkenyl group; Z.sub.2 represents an atomic group for forming an aryl group, a heteroaryl group, a cycloalkenyl group or a heterocycloalkenyl group; Y represents an atomic group for forming a 5-membered nitrogen-containing heterocycloalkenyl group; each of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents a hydrogen atom or a substituent; m is 1 or 2; a, b and d is 0 or any positive integer; and c is an integer of from 0 to 2. |