A processing apparatus includes: a processing chamber configured to contain a workpiece; a first nozzle provided in the processing chamber, the first nozzle discharging vapor onto the workpiece; a wall enclosing the processing chamber; a fluid channel provided inside the wall; a fluid inlet; and a fluid outlet.The fluid inlet is provided in communication with the fluid channel. The fluid outlet is provided in communication with the fluid channel, where a fluid flows into the fluid inlet, passes through the fluid channel, and flows out of the fluid outlet. A processing method for processing a workpiece moving in a processing chamber, the processing method includes: discharging a vapor from a first nozzle toward the workpiece while flowing a fluid through a fluid channel which is provided inside a wall, the wall enclosing the processing chamber.