A condensed heterocyclic compound which is shown by the following formula (I) and a composition containing an (a) organic material and (b) at least one type of the condensed heterocyclic compound are provided. (Y indicates a chemical single bond, —S(═O)—, or —SO2—. Ra and Rb indicate substitutable C1 to C30 organic groups. Za and Zb indicate chemical single bonds or —SO2—. X1 and X2 indicate hydrogen atoms etc. n and m respectively independently indicate integers of 0 to 2, where one of n and m is not 0).