A resist stripping agent comprising a specific alkanolamine having at least one functional group represented by the following formula (I): wherein R1 and R2 are each hydrogen atom, C1-C8 alkyl or C1-C8 alkenyl. The resist stripping agent easily and efficiently removes resist films and resist residues remaining after etching or after ashing subsequent to etching in manufacturing semiconductor devices at low temperatures in short period of time. The resist stripping agent is resistant to corrosion against materials for substrate, circuits and insulating films.