PURPOSE: To provide the subject solvent as a substitute fluorocarbon, containing perfluorobutane as the active component and suitable for removing processing oil from a precision machinery component, an optical instrument component, etc., a soldering flux from an electrical and electronic component or stains from clothes.

CONSTITUTION: The objective solvent contains 1H,1H,3H-perfluorobutane preferably in an amount of ≥70wt.% and may contain, as necessary, a hydrocarbon, an alcohol, a ketone, an ether, an ester, a chlorinated hydrocarbon, etc.