PROBLEM TO BE SOLVED: To provide a fullerene derivative having, at a specified addition position, an organic group and soluble with general-purpose organic solvents; a method for manufacturing a fullerene derivative capable of controlling the addition position of an organic group and of easily obtaining a singular fullerene derivative including no addition position-specific isomers; a fullerene bromide for manufacturing a fullerene derivative used for manufacturing the fullerene derivative; an electron acceptor, an n-type semiconductor material, and a thin organic film solar cell each using the fullerene derivative.SOLUTION: In the provided method for manufacturing a fullerene derivative, a fullerene derivative expressed by the following general formula (I) is manufactured by reacting fullerene bromide with either of methanol and ethanol in the presence of a silver salt and an organic solvent: general formula (I): C(OR)(in formula (I), R expresses either of a methyl group and an ethyl group).