A composition for forming a resist underlayer film that enables the formation of a desired resist pattern; a method for producing a resist pattern and producing a semiconductor device, which uses this composition for forming a resist underlayer film. A composition for forming an EUV resist underlayer film, said composition containing an organic solvent and a reaction product of a diepoxy compound and a compound represented by formula (1). (In formula (1), Y1 represents an alkylene group having from 1 to 10 carbon atoms, wherein at least one hydrogen atom is substituted by a fluorine atom; each of T1 and T2 independently represents a hydroxy group or a carboxy group; each of R1 and R2 independently represents an alkyl group having from 1-10 carbon atoms, said alkyl group being optionally substituted by a fluorine atom; and each of n1 and n2 independently represents an integer from 0 to 4.)