A processing apparatus includes: a tank configured to store water; vapor generating unit configured to turn the water supplied from the tank into vapor; a processing chamber in which vapor supplied from the vapor generating unit is used to remove residues from a workpiece; cooling unit; and filtering unit. The cooling unit cools waste liquid ejected from the processing chamber. The filtering unit is provided between the cooling unit and the tank, and the filtering unit filters the waste liquid cooled in the cooling unit. A processing method includes: supplying vapor into a processing chamber; removing residues from a workpiece using the vapor; cooling waste liquid containing the removed residues to precipitate the residues as solids; and filtering the waste liquid containing the precipitates.