An object of the present invention is to provide a novel fullerene derivative usable in n-type semiconductor materials for organic thin-film solar cells and the like. The object is achieved by a fullerene derivative represented by formula (1) wherein R1 represents aryl optionally substituted with at least one substituent, R2 represents an organic group, R3 represents an organic group, with the proviso that at least one of R2 and R3 is alkyl optionally substituted with at least one substituent or alkyl ether optionally substituted with at least one substituent, R4 represents hydrogen or an organic group, and a ring A represents a fullerene ring.