An endoscope processing apparatus of the invention includes: a cleaning tank which can house an endoscope a liquid drainage port, a liquid inlet port and a discharge port which are opening portions provided to the cleaning tank a first-liquid introducing section which introduces a first liquid into a multipurpose conduit a second-liquid introducing section which introduces a second liquid into the multipurpose conduit a gas-liquid mixing section which mixes a liquid in the multipurpose conduit with gas, to deliver the mixed fluid to the discharge port a liquid-feeding section which delivers a liquid in the multipurpose conduit to the gas-liquid mixing section and an opening/closing section which opens and closes a connection between the multipurpose conduit and the gas-liquid mixing section and a compressor which delivers the gas to the gas-liquid mixing section.
