A composition having an oil film retention function which an oil film can be stably retained on surfaces of various metals, an anticorrosive agent using same, and insulated terminated electric wire. A composition having oil film retention function for being added to base oil to be applied onto a metal surface and retaining base oil on metal surface, and composition contains a component that is an adduct of an azole compound and acidic alkyl phosphate ester including one or more compounds represented by General Formulae (1) (Chemical Formula 1) P(═O)(—OR1)(—OH)2 . . . (1) or General Formula (2) (Chemical Formula 2) P(═O)(—OR1)2(—OH) . . . (2) where R1 represents an organic group having four or more carbon atoms, and component that is an adduct of a metal and/or organic amine compound and acidic alkyl phosphate ester including one or more compounds represented by General Formulae (1) or (2).